Hi Kaushik. You have a good chance to secure a seat this year. The cutoff marks for SC category in BHU bsc agriculture last year was 165. And total of 169 candidates of sc category were called. There are total of 19 seats in main campus and 6 seats in R.G.S.C  for SC candidates. Seeing your rank you can definitely secure a seat. You should definitely go to the counseling after getting the call letter.