Please help.

MnC BHU or ECE/EE Guwahati ??
what should I prefer?

you like cs and math take mnc at bhu, if you like gadgets and robotics go for electrical or electronics. go by branch and not placement. placement wise they all are approximately the same. you will be much more free if you take mnc, but it could get boring if you cant love the subject. so choose based on interest. if you love what u r doing, you wont have to work ever again in your life.

all the best