I haven’t graduated from IIT or NIT ( primer college) will be able to get job in DS field if I study ML & R programming or should I prepare for GATE to opt into primer institute.
If you are good enough and have achieved a good amount of excellence in the field, it won’t matter which college you are from. You may be just starting now or you may have dabbled a bit, but I would suggest trying to give more time to it, because it will help ou get a better understanding of the scenario.
I would suggest you to go through this learning path rigorously, and I’m sure you will succeed. Good luck.
If you are interested in doing a Masters in Machine learning and Data Mining, then this university may be a good fit for you, Aalto University School of Science located in Helsinki, Finland. https://into.aalto.fi/display/enmac/Homepage I did this course from the same university and found the course pretty good, here are some answers from Quora that I have written about the course and the university
If you are looking at India, you should write GATE only if you are looking to get into IISc or the old IITs, Other than that, there is no good college in India for data science field. Coursera Online courses, certifications are better. However, I advise you to take an offline Master course for Data Science.