Hi,
I can understand your dilemma and of course, there is no right or wrong answer to it. However, I will share with you some views. When we graduated from IITM about 22 years ago, the general trend was for a majority of the students to go for Masters either within India or in the USA. However, we have seen quite a change in this trend in the last decade or so with many graduating students (not just from IITM but other institutes too) more open to taking on employment for a few years and then deciding either to continue or to pursue Masters.
From personal experience, I believe having relevant work experience in a job before taking Masters is very useful. In my own case, if I look back, I would have gotten much more value from my MS degree in the USA if I had at least 1-2 years of real work experience after my BTech. For an MBA degree, this is even more relevant. The key though is for you to try and work a job where the experience is relevant for your Masters and for the field that you would like to continue working in. At least the job should contribute to your thought process on what type of a field you may want to pursue your Masters in or want to work further in. Another consideration is if you would like to have some financial independence before pursuing Masters, you may want to take up a job.
Even if you want to pursue research all the way to PhD and want to take up academic/research work in the future, industry experience after Bachelors can still help but may not be as critical.
I also know some folks who got into a job after their BTech, have continued on and thought much later that they should pursued a Masters early on. So, something to be wary of - not letting the financial independence put further studies on the back burner.
In any case, there is no one answer to this and you may want to do what suits your circumstances the best. Happy to advise further if you have any questions.
Hope this helps. Best wishes,
Umasankar (IITM BTech Mech Engg - graduated in 1996)