I don't know if this really falls in this category--?

I do not know of such school in India, I am a special education teacher in the US...Here, if a child/student has a profound hearing loss, they have a plan in place to help the student. It is called and IEP (individualized education program.) The school should provide accommodations for your sister. Talk to your parents/adult and see if they can talk to a head master, principal or leader at your sisters school. She needs to have accommodations!! Good luck!