Hey !

By knowing that you have 86 marks in JEE advance and you are from SC category , i van not fully assure you whether you can get an IIT seat or not since the cutoffs are released in the form of ranks , not marks and moreover , different branches have different cutoff ranks. It may be possible that you can get a seat in MME but not CSE ,but you want admission in CSE only . In that case , there is no possibility. So , j request you to kindly mention your rank and preferred branch in comments so that i can help  you at my best.

You can check the previous year cutoff ranks for all IITs by going through the following link:

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

Hope it helps!