Well brother, looking at the past trends the IIIT Allahabad closes around 2.5K SC rank.

But I would like to suggest you to fill it in your JoSAA counseling, as you may never know when the lady luck falls on you. Also government allows to fill ample options on counseling, so it is best to reap it's maximum benifits.

Pro Tip - I would like to suggest to go to the spot round, as I've personlay seen uge turn out in spot rounds and this highly true among the category candidates. 

All the best

• One needs to take the Jee exam and either secure at least 75% marks (65% for SC/ST/PwD) in Class XII or be within the category-wise top 20 percentile in his/her respective Class XII board examination.
• Admissions are done on the basis of rank JEE main through JOSAA and CSAB special round