what mark I have to gain in JEE advanced for seats

Assuming you are from General Category, and moderate to tough difficulty at par with JEE Advanced 2018, 2019 and 2020 besides considering increasing number of seats each year, I believe securing 120 out of a Total of 360 (366 OR 372), or roughly 30% (~12000) ensures you a seat in B.Tech in atleast one of the IITs.

However for greater number of choices and better branches ,it is expected you target securing 40% of the Total Score and also make this a practice in your Mock Tests, so that you ultimately you achieve your aim.

For more information do follow the link below

https://engineering.careers360.com/articles/jee-advanced-rank-list/amp

Hello Aspirant,

The cutoffs for IITs will vary based on the level of competition, number of seats ,difficulty level of the question paper,number of applicants ,highest mark scored etc. But generally for a good rank in JEE Advanced the minimum score required is 30% but to be on the safer side try to score atleast 40% of the max marks (~160 out of 400). Since the number of people writing JEE Advanced is comparatively less than JEE Mains , score an average mark itself gives you a good rank. For the old IITs the ranks required will be higher than for the new ones and based on previous year trends a rank below 4000 may get you into IITs.
The qualifying cutoff for JEE Advanced 2019 catetory-wise:
General Category--89.75
EWS--78.21
OBC--74.31

This link will show all the 2020 cutoff for various IITs, do check it out :

https://engineering.careers360.com/articles/jee-advanced-cutoff-for-iits

All the best