No its all same. PhD also have an interview for sure and for PhD apart from GATE they also consider previous acads too. Like GATE Score, Engineering percentage, 12 and 10th class results can also be considered.
For M.Tech admission this is not important until its a tie.
The best thing is to carryout some research so that when you land there you have a purpose to achieve. Just dont make landing in US your target. A good research position in IITs would be great for you. Look for those opportunities.
Good luck ahead.
Dont be confuse. Take a call give your best efforts for it. Thats the only way to realize your dreams. Give you best try, honest best try and leave it to GOD you will have peace and success in life.
Please ask this question in PhD forum.