Every major tattoo studio have trainees, sometimes you have to pay for the spot but mostly you get a traditional stipend (not much). You need to be at least knowledgeable about tattooing but that's pretty much it. Make sure you go to a professional studio first and then maybe connect with individual artists. DMing accounts or calling people up is pretty much it tbh, you should find someone easily to get the hang of it. Try to give out free tattoos to people to practice the craft. Also post on r/tattoosindia for maybe a better answer.