Hi dear,

I appreciate your interest in programmimg at this stage. To write GSOC exams, there are some criteria.

The student must be at least 18 years of age when you register.And you must be currently be a full or part-time student  at an (https://developers.google.com/open-source/gsoc/faq#accredited) university. Considering you are in grade 11, you cannot write the exam.

So, lets wait a little, till then practise programming.