If anyone wants to to do research and join organisations such as DRDO,ISRO etc or to teach in the engineering colleges,then it is better that they do their Masters degree.Other wise I don't think it to be necessary.
Because,most of the time people who don't get their placements try to do their Masters degree just to add value to their qualification.So,if we get the job in the campus interview,then it is better to go for the job than doing Masters degree.If anyone is so interested in studying,then they can do their MBA through distance education,which will widen their job opportunity.
scincgprof is right, if you want to enjoy student life further, go for masters, because it will develop your personalities,,, and part time jobs with masters degrees are readily available.. and you might get a scholarship for masters degree...
Both of above gave right answer. If u get a job after b.tech. then go for it. Where u can pursue executive MBA programme to get promotions in job.
And if u have keen interest in research, or want to be Assistant Professor can do M.Tech./M.S.
You can also work as Scientist B in DRDO, after qualifying DRDO exams.
JTO in BSNL is after B.Tech.
IOCL requires GATE percentile.
So it depends on your interest and current situation whether you want to go for P.G. or not...