The admission will be based on Jee main score only as there is no separate test for NSIT, DTU, IIIT D, IGDTUW but yes, counseling will be conducted through Jac Delhi as you will have to apply for the same separately. Also, to check cut off from first to last round of Jac Delhi you can go through the below link -

Cut off 2017

Hope this helps!!!

It takes admission through JEE Main only counselling is held seperately.

Yes, it is tough you need to prepare well for your exam. You need to do lot of practice. You should be determined and motivated to crack your exam.

You should score more than 150 marks in Delhi Region, General Category to get these colleges and more then 200 marks in Outside Delhi Region in General Category to get these colleges. Cut off marks vary according to the branches.

To check the cut off rank you can refer below link

JAC Delhi Cut off

Good Luck!!