If you are sure that you can apply for stream upliftment and change it to ECE or IT in Kalyani Engineering college, then you should wait for 2nd or 3rd counselling. But if you unsure, then studying a stream like mechanical, completely opposite to your choice is no good.

KGEC can give you better placement than JGEC, the only reason being it is located closer to Kolkata than JGEC. Few companies come to college and recruit students.  ME & EE department are very strict and demanded a lot of discipline. Being government colleges as usual, you have to give your own efforts. There is a huge communication gap between the faculty and the students. Also KGEC comes just after JU in WBJEE couselling.

If you are not getting your desired stream in KGEC(because closing ranks are lesser in KGEC than JGEC), then you should study in JGEC with your preferred stream. If you are getting your preferred stream in both the colleges, KGEC is definitely better because of better quality of students and proximity to Kolkata.

There are also some other factors to mention. The location is really preferable for KGEC, as you can get easiness from transport to all other regular needs. Jalpaiguri has a pleasant weather; but where as Kalyani has a warm weather.The campus area of JGEC is 167 acres whereas KGEC only comprises of 75 acres area only. The food quality of JGEC hostel mess is far better than any other state government hostel mess undoubtedly.Medical facilities, electricity, water usage, wifi and LAN(8–12mbps speed), all are totally free in JGEC. KGEC and JGEC has almost similar infrastructure, but popularity of KGEC is much more than JGEC as because it is situated near Kolkata. Mentioning about clubs and fest, Sristi is the largest technical fest in North Bengal; Also the cultural fest JECLAT promises every year with great bands, big singers to modern singers, big national and regional bands and fashion shows, which are all in much greater scale than any other state college fests.Placements are undoubtedly better in KGEC; JGEC has downgraded in terms of placement.