“Best” is a subjective word and depends on factors like what you are doing now, what’s your motive to do mtech or joining psu, whether you are interested in research or not etc.
Based on my experience, some people do mtech because they want to get good salary package, some people do to go in research. Similarly, some people join psu for job security and do not want to take much work pressure etc.
And, there are some people who don’t have any motive and guidance but they want to make their life better than what they are doing now, so they try every possible thing.
So, depends on the factors like above you can choose where you have to go. It is difficult for me to say you should have to go here without knowing things like above. But I always say, try every possible thing which have a similar pattern and after clearing everything, then decide where you have to go.
Like always prepare for psu exams or any other exams which are similar to gate, it should not be like I have to do mtech from IITs/IISc, so I will prepare for gate because there is a risk involved in it if we only go for a particular thing But if you try for other exams like ISI,CMI,TIFR,IIIT-H,BITS,JEST,ISRO,NIELIT etc along with gate then if one day doesn’t go well then other day will be yours if you have prepared well. And, all these options are enough to make your life better, so according to me anyone would be suffice if you do well where you go.
All The Best :)
