Hey !

Three rounds of counselling for DU JAT are sure. And rest rounds of counselling depend upon the number of vacant seats left after three rounds of counselling. If the seats will be left vacant , then there will be further rounds of counselling , otherwise not. So , at present tjme , nithing can be predicted about the number of rounds of counselling.

And yes , last year , there were five rounds of counselling. 

You can check the cutoffs for all five rounds of counselling by following the given link;

http://www.du.ac.in/ug-admission-lists.html

Hope it helps!