15ca /cb exchange rate

Invoice booking date would be 07/08/2019 & GST RCM Liability date will be same with given Rate of Exchange 71.61

Payment date will be 04/09/2019 & excess amount will be booked as Exchange Variation Loss with Rate of Exchange 71.85 But in your case if bank is charging with ROE 71.61 then you have to booked this entry with same rate & no loss will occur.                                                                                                                                                                                

and what about TDS? shall i deposit tds as mentioned in 15CA/CB or taken invoice value and duduct TDS.