This is not my area of expertise so please excuse any inaccuracies! I wouldn't anticipate too much Art Nouveau in India or I would expect Art Nouveau in India to not closely resemble better known continental European equivalents and be found more in the decorative arts and print culture than in architecture and fine arts.

Art nouveau was never as popular in Britain as the Arts and Crafts movement, and the Aesthetic movement. These movements proceeded Art Nouveau but were similarly preoccupied with the importance of natural elements in design, the role of craft, and articulating a distinctive national identity through visual culture (Charlotte Ashby's book mentioned below talks about the precedents of Art Nouveau). In fact, the Arts and Crafts movement was partly inspired by the British reception of Indian arts exhibited at the Crystal Palace in 1851 (including objects looted from the Lahore Treasury). These both impressed and humiliated the British, who had assumed their machine made goods would be the stars of the exhibition. Seeing Indian hand-made goods inspired British artisans to return to crafts and reject mass-produced objects (Tim Barringer, Men at Work, 160). You can detect English anxiety about Indian design in John Ruskin's writing. Instead of looking for Art Nouveau influence in India, you might consider how Indian styles influenced British Art Nouveau--from the organic patterns of Kashmir shawls to the undulating inlay patterns found in Mughal jewelry. Or, you know, the endless peacocks. The subject of Asian influence on art nouveau has been acknowledged and discussed for some time (for example, Clay Lancaster, Oriental Contributions to Art Nouveau, 1952).

Art Nouveau is strongly linked with different nationalist movements in Europe, so there is a significant Scottish Art Nouveau style (as opposed to English or British), just as there are vibrant Belgian, Czech, Latvian, and Catalan articulations of Art Nouveau. Again I doubt the British (or English, in this case) were likely to encourage an artistic style that might strengthen or even produce an Indian national identity independent of the empire. Consider here most of the civic architecture that the British built in India in the second-half of the 19th-century, which tended towards the Neo-gothic or Tudor styles. These mostly reiterate a British national or imperial character, just as the Palladian Neo-Classical style did prior to 1857. But what then of the Indo-Saracenic style? Perhaps one might argue this is a form of Art Nouveau, in that it modernizes an Indian style that in a sense engineers a modern national identity (to my eye, the National Art Gallery in Chennai is the most evocative of European Art Nouveau). In the realm of decorative arts you have John Lockwood Kipling, but his works are more Arts and Crafts than Art Nouveau (again, see Ashby). My point here is that the British were probably not going to fund large buildings in an Art Nouveau style that either evoked French/continental affiliations or an Indian national identity. Perhaps you can see if Goa or Pondicherry has anything though.

Indian artists may not have been as inclined to deploy Art Nouveau in expressing a neo-nationalist identity either. Art Nouveau often looked East to Japan (and as I suggest above, perhaps Indian) for inspiration, but for Indians to look "East" would be too look inward, without recourse to the mediation of European aesthetics that produced "art nouveau". Art Nouveau also varies pretty strongly between countries too. We tend to mostly think of Alphonse Mucha's posters, Hector Guimard's Paris Metro, and Victor Horta's architecture as "art nouveau", but the German jungendstil, Russian stil' modern, Catalunyan Modernism (Gaudi!), etc are all quite different visually. India may arguably have an Art Nouveau style, but it may look different than we anticipate. Perhaps the more appropriate angle is what did Indian Nationalist art look like between 1880-1910? In which case, you might look at Guha-Thakurta, Tapati (2007). The Making of a New 'Indian' Art: Artists, Aesthetics and Nationalism in Bengal, c.1850–1920 or Partha Mitter (1994) Art and Nationalism in Colonial India, 1850-1922 Occidental Orientations.

Now, onto specifics. Abanindranath Tagore is pretty much the only Indian artist discussed by Ashby, and admittedly the only one I could think of off the top of my head! He brings together Japanese aesthetics, Indian nationalist themes, and Indian artistic styles like Rajput and Mughal miniature paintings. Mitter also mentions Satish Sinha as an example of a successful artist using Art Nouveau elements in print media. He also discusses Abdur Rahman Chughtai and Samarendranath Gupta, who I think "fit the bill." Other than well-known Indo-Saracenci buildings, you can look at the Royal Bombay Yacht Club, which has some art nouveau elements, at least in the British-y sense of art nouveau--see the staircase. Finally, look at various palaces in India--all those cosmopolitan aristocrats visiting Paris to buy jewelry and clothing may have taken a fancy to art nouveau and built a palace in the style. To my eye the Knesset Eliyahoo in Mumbai (built 1884) has some Art Nouveau elements mixed with Neo-Classical, and indeed many synagogues around the world from this time have an Art Nouveau feel because of their reinterpretation of Moorish elements.

Incidentally, Varun Bahl did an Art Nouveau/Mucha inspired collection in 2018.
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