I have a pc with internet connection from Sify

Sir,
I have a pc with internet connection from Sify.
I have taken cable connection from sify for 6 months.
I pay an average of Rs.550 per month.
I have a BSNL telephone connection.
Our area that is Nallasopara in Thane in Maharashtra is having power cuts for about 6 hours per day.
Whenever electric supply is not there, I will not be able to get the internet connection.
When I enquired with some friends they told me that if BSNL connection is taken it will be around Rs.400 per month for 24 hours connection.
When I visited BSNL’s site I found that if I apply upto 31st March the connection is free and thereafter it will be minimum.
But I am not following what exactly I should pay.
Please any body advise me a better cheap way of getting 24 hours unlimited internet connection at home.