USDINR Expiry time

when will the usdinr20octFut instrument will expire, expiry Date shows as 27-oct , but at which time? end of the day at 5 pm, read about rbi announce us to inr conversion rate ,do they announce at 5pm on oct 27th ?
how forex instrument expiry works? same as futures and options?

Currency F&O will expire at 12:15 PM, and will be settled at Reference Rate which RBI declares at 1:30 PM. You can check these rates on FBIL or NSE website.