Dear Yashvardhan Borse,
The QR Code print size depends upon the printing material or the merchandise used. Generally, if the code is to be used in a small to a medium-sized product, (e.g. flyers or business cards), the size of the QR Code should be at least 0.4 inches x 0.4 inches (1 cm x 1 cm).
The minimum size of a QR code is 2 x 2 cm, or roughly 0.8 inches x 0.8 inches. There is no standardized QR code size, and QR codes can actually be smaller than 2 x 2 centimeters.