Why it happens
Why strong Indian applicants lose places they should have won
The short answer
Rarely because of grades. Four causes recur: a percentage or CGPA left unexplained so a committee cannot place it, a CV rewritten as prose, a fit paragraph that names reputation instead of research, and a plan that stops at graduation. All four are avoidable and none requires a better academic record.
An unexplained grading scale
A committee reading a 72 per cent has to know whether that is excellent or ordinary at your university, and many will not do the work of finding out. One line stating the scale, the class of degree and your position if you know it settles it.
See CGPA to GPA conversion for how the conversion is usually handled and where it goes wrong.
The CV rewritten as prose
Listing what you already submitted elsewhere in the file uses the one document where you could have explained it. The committee has your CV. What it does not have is why the third project changed your direction.
Reputation given as fit
"Your esteemed university's world-class faculty" is written by applicants who did not read the department pages. Naming a specific lab, module or paper takes an hour and is the difference between a statement addressed to this programme and one addressed to any programme.
A plan that ends at graduation
Committees are assessing whether the degree leads somewhere. A statement that stops at "complete my master's" leaves the reader unable to say what it is for, and in destinations like New Zealand and Australia that coherence is weighted explicitly.
Related questions
Is my percentage too low to apply abroad?
It depends on the programme's stated minimum, which is usually published and is a hard filter. Where you clear it, an unexplained scale hurts more than the number itself: one line stating your university's grading convention and your class of degree lets a committee read the figure correctly.