To get colleges through CSAB counselling, you first have to be JEE Main qualified. Now for SC category, the 2019 JEE Main cutoff is 54.01 percentile. Since you have 56 percentile so you are JEE Main qualified and eligible to get a seat through CSAB counselling. But the thing is, as per your rank it may be difficult for you to get a good seat. You might be able to get a seat but can't say for sure. So better attend the CSAB Special Round counselling and see which NITs,IIITs,GFTIs are you getting and in which branch.

You can go through this link and checkout the details regarding CSAB Special Round : https://engineering.careers360.com/articles/csab