They provide official transcript from balkhu...but to get that officail transcript you have to show your original transcript and graduation certificate..They don't issue that without showing origianals, So if you have your original here with you, the best way is, send that via Fedex or USPS to Nepal and tell your relative or friend to collect that and make the official transcript for you from balkhu and send the official transcripts to the universities you are applying. I did the same...my brother did all those stuffs for me. It takes  around $50-$60 to send the transcript to Nepal. It just takes 1 day to make that official transcript.
Don't forget to tell your friends/ relatives to take required number of envelopes and copies of your transcript and certificate with them.They just do the attestation and sealing of envelope with TU stamp there I guess.
And also, while  sending the attested official transcripts to the universities you are applying  tell them to put the address of balkhu on the envelope of Fedex .

Hope it helps.