Dear Aspirant,

Most of the colleges do not have any age limit for their MA courses. And regarding the gap in between your studies, there shouldn't be any problem as you were employed in a school.
Don't worry about the change in stream. The basic eligibility criteria states the requirement of a bachelor's degree with 50% and above aggregate from any discipline. Though a degree in Hindi is usually preferred.

You may need to produce a character certificate from your service authorizing centre.
You can pursue your post graduate degree in M.A. (Hindi) from colleges or universities where there is no age limit by clearing entrance exam conducted by the concerned institute or on the basis of merit as per their admission guidelines.
For more information, kindly provide us the name of the college or university in which you are interested in the comment section.

Hope this answer will help you.