Nope! For any online counselling, you need to give preferences of minimum 10 colleges based on your interest. Now if you have preference for only one college, then you keep the name of that college on the 1st preference and fill other colleges which you can feel like if you don't get a seat, then you can pursue your education from it.

Its better to have multiple choices as which college one will get, is dependent on the rank and the rankers appearing in the counselling putting the college in preference. So to be safe, do have some multiple choices and make the 1st choice, the college you really want.

I hope this answer helps. All the very best for your future endeavors!