This is a Portuguese India postage stamp, featuring the portrait of King Carlos I of Portugal, issued in the early 1900s. Printed in green with an ornate floral frame, the design includes the inscription “INDIA PORTUGUESA CORREIOS”. This example shows a black surcharge of 6 Reis over an earlier face value, reflecting a postal rate adjustment. Such surcharges were commonly applied in Portuguese colonies due to currency and postal changes. Stamps like this are prized among collectors of colonial Indian philately, as they showcase the intersection of Portuguese imperial history with South Asian postal heritage.