Dear Aspirant, 

The preparatoy course counselling for SC\ST category students is also taken in the JOSSA counselling. There is no seperate counselling for this. For this you will have to pay registration fee, get the documents verified as per the schedule. And fill in choices and wait for the allotment results. This is the process for 7 rounds in JoSSA. 

Hope this helps. 

All the best.