₹0.50 domestic postcarda government-subsidized rate that hasn't changed in decades. just stick a ₹1 stamp (₹0.50 stamps are rare) or get actual postcards from the post office — they come pre-paid.
₹15 flat for international postcardworks to any country. use a stamp or ask at the counter for a franking.
use airmail stickersblue "PAR AVION / AIRMAIL" sticker is free at post offices. without it your international mail may go by surface (slower, same price).
writing the address4 lines max on the right half. leave the left half for your message. country name in capitals on the last line.
stamp placementtop-right corner, face side. if you stack multiple stamps, don't overlap value-bearing parts.
drop box vs countercounter-posted mail is date-cancelled same day. drop-box mail may wait till evening pickup.