That's a pretty good rank in JEE Mains. No worries in getting admission into a good engineering college.

Based on his rank i.e. 6462 in Common Rank List, there are colleges available like-

1. NIT Delhi

2. University of Hyderabad

3. NIT Jalandhar

4. NIT Kurukshetra

or there are many best private universities options also available like SRM, VIT, Amity University, LPU Punjab and many others.

Regards,

Keshav Sahani

Congratulations to him 

You can opt for NITS like Warangal, Trichy,surathkal, Nagpur,DTU etc also you can opt for IIIT Hyderabad if he is interested in cse or IT.. Best of Luck....