From where should I do internship for civil engineering...which is best for me?? I am a student of India's ranked 9 college

You can choose the topic as per your interest. These are the three main sub branches of civil engineering. 1) Environmental engineering
2) Geotechnical engineering
3) Structural engineering For environmental engineering-
There are options for you like NCAOR, NIO, NGRI etc.

For Geotechnical engineering- There are options for you like Larsen and Toubro, DMR, HMR

For Structural engineering-

You can go for Larsen and Toubro, RITES limited

Good Luck!