Both NIET, as well as GNIOT, are private engineering colleges affiliated to the Dr. A.P.J Abdul Kalam Technical University (AKTU), Uttar Pradesh. In normal circumstances, you should go with the branch of your choice. But I will suggest that you consider taking ECE at NIET.

NIET is far ahead of GNIOT in rankings, placement, and basically every other parameter. If you are not getting CSE at NIET, then do not worry. There is another way.

At AKTU all the students of every branch of engineering study the same subjects in the first two semesters, i.e. in the first year. So if you study ECE or CSE, it does not really matter. What matters is studying well and scoring more than 75% on aggregate in the first year. Then you can approach the registrar and apply for branch change to CSE in the second year. The actual CSE subject starts only the second year so you do not miss out on anything.