Can we increase height even at age 24?

Not without surgery.: An adult stops growing after the epiphyseal plates (growth plates) of their long bones fuse together, which typically happens in the teenage years. After that, the only way to increase height is by bone-lengthening surgery, where a surgical break is made in the shin bones and an apparatus is inserted which allows a doctor to, day by day, painfully split the bones apart. You only get 2-3 inches.

No: Genetically pre determined. No proven, safe way to do.