Tds deduction

Please clarify this payment done on 14/09.2018 is completely different from the payment mentioned earlier.

the transaction is like this

payments from 21.7.18 to 7.9.18- Rs,1,20,000/- (every time deducted tds on payment amount)

expense booked on 14.9.18-Rs.3,20,065/-

payment made on 14.9.18- Rs,1,50,000/- 

tds to be deducted on which amount? ( i have deducted on Rs.1,50,000/-)

here it should be on expense amount Rs.320065/-less tds already deducted on Rs.120000/-i.e.on Rs.200065/-?

TDS should be deducted at the time of payment / credit to party account. In your case it should be deducted on balance Rs. 2,00,065/-

but now the f.y.has been closed i have deducted tds on Rs.1,50,000/- instead of Rs.2,00,065/-

how to rectify this?

tds return has not filed yet for the Q4 of f.y.2018-19

but if tds not deducted as stated above, which amount will be disallowed?

means if i pay the amount now (short deducted tds) & shown it in tds return of Q4 of 2018-19 the expense amount won't get disallowed?

thanks to all the experts for the valuable information.