im from an indian family too and i can understand how strict they can be. My parents expect me to get a levels, get a highly paid job and get a good wife when im 25! And most indian parents expect the same thing.
Im sorry to say, but I think your mum isn't going to be too happy. Many Indian parents want you to be a normal successful person, and too them being gay isn't normal. However Indian familes have started to change. My parents were extremely strict indian family, and they still are. However they have eased up a little. Hopefully your parents have too.
However you have to tell them straight. Get your mum and dad in 1 room but not the rest of your family. Turn off all tvs radios etc and tell them. When you have told them, let them decide what they think and what they think you should do. Hopefully they will accept, or even will not mind your sexuality. However do not tell the rest of your family at the same time. Let your parents decide firstly if they want to tell your family. If they do not and you want to, this might cause too much stress for them, as I know Indian familes keep personal news too themselves and im afraid to say, even if they accept the fact that you are gay, they might not like the rest of the family to know. I have overheard Indian parents taking about people behind their backs, and im scared that your parents will not want the rest of your family to talk about your sexuality.
But whatever you do try not to argue with them. Indian familes are rash. My dad has nearly kicked me out of house once when i lost my temper with him and just shouted at him! However my mum saved me. So just let them do what they want, if just letting them know you are gay is enough.
Hopefully you do not have a typical indian family as I have described. However Indian familes are changing to western ways so they might be ok with it. GOOD LUCK. SORRY IF I HAVE MADE IT HARDER FOR U!