Hi Sam!
Not every company looks at the place from where you qualified your class 12, but I will not say that it doesn't matter also.
So, I suggest that you focus more on becoming more eligible for a job by improving your skill set so that there is no chance given to the employer to raise a question about your qualification.

Since you are still in Class 12, this is the right time for you to decide about your career and take steps towards it.
Let me know if this answer helped you and all the best for your future.