how many marks are required to get seat in IIT for SC cateogry 2021 and as to get in CSE branch.
In JEE Advanced 2019, securing anywhere around AIR 11-13k, your SC Rank would be anywhere around 200-250. At this Rank you have chances of securing CSE at some of the Second Generation IITs, be it Indore, Hyderabad, ISM, BHU, Gandinagar, Bhubaneshwar and many more with IIT Jammu closing at SC Rank 1397. However, as a target you should aim securing atleast a SC Rank within 250, a Corresponding AIR within 13-15k, and probably Score Target in JEE Advanced (Considering 360 as Total Score) above 90-100, preferably above 100, considering the moderate to tough Paper across last few Years. Of course scoring lower you'll still have prospects among IITs as well as lower branches like EE, ECE, Mechanical and many others with equally good Prospects.