Based on the fact that afterall its the norm of Indian shows to show the main charachters very white, I totally believe in Krish's innocence and Rajni's sincerity in avenging her sister's present state. Because, toward the end , did you notice, Rajan (Krish's brother-in-law, not sure if that is his name) has his bags packed and ready to leave the house and encouraging the whole family to leave with him. He is afraid of something and wants to get away from the house. What I think is that, when the wheelchair girl was agitated - it was because she saw him and not Krish as her aggressor. It must have been Rajan who is responsible for putting the girl in the wheel chair. Furthermore, being a part of the family, he has access to Krish's pictures and other details. Very deceitfully he used poor Krish and framed him, after knowing the girl was a vegetable and would not prove otherwise.
Now the question is why Krish?? Simple, with Krish out of his was, he gets to inherit the family fortune and business.
Just my take, I could be wrong.