Likely it was a sporting rifle built in Belgium post-WW1 in 7x57 on an ex-Kar98AZ action. Later someone added the prestigious Mauser banner, Mauser-Werke inscription, the "Cal.7mm" inscription and perhaps restocked it. A German postWW1 would have rather written "Kal.7mm" and 7mm appears on the barrel two times. Also, compare the MW inscriptions on the left receiver wall. On top is the one on this Belgian-Indian Mauser, below the one on my rust-pitted 7x57 B-Mauser, large ring intermediate action, of 1933 vintage. Look closely at the shape of the "M" and of the "A/N".

I would buy it as what it is: A fairly old and mediocre 7x57 working bolt action on an ex-military 98 action, but not as a Commercial Mauser sporting rifle. Don't pay a single Rupee for the faked "Mauser" and "Made in Germany" inscriptions.