Hi Abhishek, 

IIT Dhanbad and IIT Patna both belong to middle tier IITs. But Dhanbad is mostly preferred by students in jossa because IIT Dhanbad is better than IIT Patna in some aspects. 

Here are some comparisons of IIT Dhanbad and IIT patna. 

• The average salary package in IIT dhanbad is higher than IIT patna.
• IIT Dhanbad is better than IIT Patna in terms of research oppurtunities.
• The campus infrastructure of IIT dhanbad beats IIT patna.
• IIT Dhanbad got more PPO's than IIT patna-both jobs and internships.

Hope this helps,

All the best!