Fire-Boltt Ninja 3 smartwatch, one of the cheapest smartwatch @ ₹1799

It has all the required sensors including blood oxygen and heart rate monitor.

It has IP68 rating which makes is water resistant. 

This smartwatch has 1.69 inch big lcd display with full touch controls.

It has 60 plus sports mode and over 100 cloud based watch faces.

Over 69k buyers rated it with 4.1 stars out of 5. it means the watch is good and value for money.

Fire-Boltt Ninja 3 smartwatch is available at amazon with price ₹1799