STEPS TO DO ONLINE PREPAID RECHARGE:-
STEP 1:- First of all, GO to BSNL Portal website.Search BSNL Portal on Google or Click Here
STEP2:- On BSNL Portal Homepage click on Sign up to create a user id As shown in screenshot:-
Note :- for top up just fill your recharge amount in the box and press submit.
You have done the online recharge process.If you still have any doubt then feel free and ask in comment box We will get you soon.