Hi neerajlall2k,
Only Citibank debit Cards are accepted by eBay Paisapay system. If you want to change the mode of payment from Others to PaisaPay then you can contact the seller and ask him to send you a revised invoice with PaisaPay as a payment option.
Please note that only if seller has offered PaisaPay as a payment option in his original listing only then he would be able to send you a revised invoice with PaisaPay option.
Qutub