which institute are best?

I think you better find a school that teaches individualized instructions. Here in the Philippines, we have Angelicum College. They are very good with slow learners. My kid could not catch up with regular school. Her average grades is from 78 to 80 for the last 7 years of schooling. I sent her to Angelicum which is a modular school where children learn at their own pace. They won't be able to go to the next lesson if they have not mastered the first one. After one year in that school my child was able to catch up with regular school. She's now back with regular school as it is much cheaper than Angelicum. Now her grades range from 85 to 88.

I am one that believes that no institutes or schools have the power to change a person. What they do have though, is the power to help a person want to change themselves.