Dad Ke Liye Kya Hoga?

Rohan, a 16-year-old, lives with his mom in Mumbai. Last year, his dad left the family due to a long-standing marital dispute. Since then, he hasn't provided any maintenance. Rohan's mom is now in a live-in relationship with her colleague and is planning to move cities for her new job. Rohan wants to stay back in school, but his mom is considering taking him along to avoid further expenses of his upkeep. Meanwhile, Rohan's dad has sent a letter stating that he's not willing to give any maintenance if Rohan is taken away from his mom. What legal remedy can Rohan's mom avail? Is Rohan entitled to any specific rights?