as per provision you have to deduct tds at the time of payment of every installment and should be deposit within 30 days after the end of month in which u paid.
therefore you have to deduct tds on your 1st installment and it should be deposit upto 30th July 2018,
since you are still now in period you can deduct and deposit it
Yes it should be assumed that you paid 99% and 1% deducted as TDS
your total tds will be depsoited on transaction will be Rs. 122872.96 ( 1% of 12287296)
and net payment will be Rs. [deleted] = Rs 12164423
deduct and deposit the tds on every installment