Sachin, whether you will get a distinction award or zonal medal or not depends on various factors like your class, difficulty level of question paper and your relative performance w.r.t. other students of your class (school, zone as well as national level). We cannot predict it on the basis of last year cutoffs. Also the cutoffs vary from zone to zone and no such cutoffs are released officially by SOF.

Zonal awards are given if you rank in 1 to 25 from your zone. The detailed awards and recognition can be viewed from their official website: http://www.sofworld.org/awards