Question

In most part of India nylon clothes are not worn

Answer 1

The climate of  India is described as hot and humid, hence in most parts of India nylon and polyester clothes are not worn because they have less air spaces in them and they do not absorb sweat.

Answer 2

India, in general is a hot and warm country. Synthetic clothes like polyester and nylon does not allow air to pass through, thus, it becomes more warm.
hope it helps you