Hey aspirant, admission in IITs are given on the Basis of cutoffs which are rank based.

Thus marks can vary year to year for Jee advance exam but ranks needed to be secured remains almost the same.

But if we take an estimate then if you are able to score more than 150 marks then your rank can come under 6000 at which rank you can get into most of the IITs.

Jee advance exam is only based on concepts and thus its difficulty level may vary for each candidate.

I hope this helps.

Please do check the previous year cut offs for various IITs on the link below:

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