Dear Aloke, for pursuing any Master's degree, the basic eligibility criteria is that you should have studied that subject in your Bachelor's. Now for languages like  pursuing Masters in English, you should have studied your graduation with English as one of your subjects in the 3 year course duration. So if you studied English in your graduation, you are eligible for MA English. Some institutions demand a minimum aggregate of 50% in your graduation. Some institutions give admissions based on Merit and some based on Entrance examinations. I didn't come across any age limit atleast until now. However this is general information. I would suggest you to check the official website of the institution that you want to get into to check if they have any age limit. Good luck!