Abhi to check out whether you can get any IITs with 3400 ranks you can go through links given below. You can check the last year cut-off of every individual branch available to do M.Tech in every IIT and NIT in the links given below. This will help you in estimating the possible branches in possible IITs and NITs so that you can apply in the specific college within the application deadline.

• You can check the list of IITs which you can expect at your GATE score from the link given below: https://engineering.careers360.com/articles/gate-cutoff-for-iits
• You can check the list of NITs which you can expect at your GATE score from the link given below: https://engineering.careers360.com/articles/gate-cutoff-for-nits

Or if you are not interested in doing higher education then you can look forward to work in PSUs. With your such a good score you will have a lot of opportunities to work in top PSUs in different fields.

To check the last year cut-off of different PSUs in different specializations you can go through this link: https://exams.collegedunia.com/gate/psu-cutoff

Feel free to ask if you have any more queries. All the best!!