Yes it can be possible

It is relative score not exact marks .

As 52 11 and 12 are individual subjects percentile score. Means 48percent students score more than you in chemistry 89 %students in physics and 88 %students in mathematics.

But when your total marks is calculated than according to the total marks your percentile is 11.

Like in chemistry highest marks is 70 and your marks is 50 similarly other students between 50-70

But highest marks in physics is  110 and your marks is 20 and other students between 20-110

It will effect a lot in your total marks percentile.

Any other query ; you can ask .

Good luck