15 months PP. Can I start regular exercises which includes lifting dumbbells?

15 months after delivery it’s safe to workout again. Though if your goal is to lose the pp belly fat, just lifting weights isn’t going to be enough. Check this out for some dietary and other tips https://sg.theasianparent.com/tips-for-a-flat-tummy-after-pregnancy-2/amp

15 months pp is generally on the safe side to start exercising already. But I think lifting dumbbells won't help if you're trying to lose the tummy.

erm 15m pp confirm no issue. but lifting dumbbells alone is not sufficient to lose the belly

Consult your doc first please. Every pregnancy is different.