Namaste sir jastai mero fixed asset xa computer 5 year dekhi depn vairaxa aba maile beche bsv 10000 xa csv pani 10000 mai beche maile sarkar lai vat kati tirnu prxa

In case of VAT, VAT amount is calculated on taxable value which is sales value before VAT. so in your case irrespective of the book value, VAT will be calculated on Rs. 10000, considering it is the sales value in your question.

Book Value is used to calculate accounting profit on sale of fixed assets. However, as per income tax provision, sales value will be reduced from the pool value of corresponding Asset Pool (for computer - Pool B).   

mero fixed asset ko bsv 10000(taxable) xa maile 10000 (taxable) total 13000 ma beche maile aba monthly vat kati tirnu prxa sarkar lai?

kei bujiyena mam

Are you clear on concept of VAT?

Ekpatak sales gareko goods lai monthly Vat tirnu parne hudaina hola.