Assuming it's a power reserve issue and it's not stopping because there's not enough clearance between hands and crystal (does the hand stop all the time in the same position?) or because something floats in the case blocking the balance wheel:
1. Ask a watchmaker to check it and fix it
2. Replace the movement on your own, if you have tools and a basic knowledge you can make it. If you consider the watch a keeper, consider to upgrade to a swiss movement (SW300 or ETA2892)
3. Sell it at a loss
What you can do on your own is: opening the case back and check if something like a spare screw or tab randomly blocks the balance wheel.