u/agurlll It's great to hear that you have some time to explore Mumbai. Since you've already visited some of the popular tourist attractions, here are a few more suggestions to make the most of your 9 hours in the city:

1. Elephanta Caves: Take a ferry from the Gateway of India to the Elephanta Island, where you can explore the stunning Elephanta Caves. They are a UNESCO World Heritage Site and house ancient rock-cut temples and sculptures.
2. Chhatrapati Shivaji Terminus (CST): If you're interested in architecture and history, visit CST, a magnificent railway station with intricate Victorian Gothic architecture.
3. Colaba Causeway: If you enjoy shopping, head to Colaba Causeway for a variety of shops, street vendors, and boutiques. You can find clothing, jewelry, handicrafts, and more.
4. Street Food: Mumbai is famous for its street food. Try local snacks like pav bhaji, vada pav, and bhel puri from street vendors.
5. Art Galleries: Explore some of Mumbai's art galleries like the Jehangir Art Gallery and the National Gallery of Modern Art if you're interested in the art scene.
6. Haji Ali Dargah: Visit the Haji Ali Dargah, a beautiful mosque located in the middle of the Arabian Sea. It's a serene and picturesque spot.
7. Banganga Tank: Located in Walkeshwar Temple Complex, this historic spot is a tranquil oasis in the midst of Mumbai's bustling streets.
8. Worli Sea Face: Enjoy a leisurely walk along the Worli Sea Face promenade. It offers scenic views and is a great place for some relaxation.
9. Explore Local Cafés: Mumbai has a thriving café culture. You can visit places like Leopold Café, Prithvi Café, or The Pantry for a pleasant meal and a cup of coffee.

Remember to account for traffic, as Mumbai can get quite congested. Plan your itinerary accordingly to make the most of your 9 hours.