At last, somebody wants to come to India
On a more serious note, I know the guy behind an NGO school for deaf and dumb kids. If you can teach them, I can talk to him.
No offense but, I don't think anybody would be able to teach English within 2-3 weeks. Is there a reason why you're so particular about that? If you're willing to get into other stuff, then I can try to work something for you.
I don't think Pakistani nationality will be much of an obstacle. Once you get a visa, you're good to go. Nobody will bother you once you land here. Where do you live?
PS - Try UNICEF, I know they have a mission/office/some sort of presence in Hyderabad.