Hi Parijesh,

It is not mandatory to attend counselling of any college but if you can then it is good because it will let you have the branch you like because after counselling get over for your slot it is not possible for the college even to a lot you the branch which you wish for they'll allow you in branch whatever they are left with or if you wish for your branch go on by management quota and land up paying a hefty amount.

If it is not the college you have to be in at any cost; you can leave or if it is genuine reason try contacting up the college management. 

Hope this helps you.

Thanks!!