Does it have a scent? Can you look at the flowers and tell us if they are Labiatae? Or post another picture?

Its a plant in very bad shape.I will uplaod soon...

Looks like an Alternanthera dentata grown in dense shade, never fed, never pruned --- ahhh, never mind :)

Regards.

What should I do now???how to prune??

Close up of leaves and bloom at d end of stem

Leaves

Cut it back and fertilize it.
Give it full sun, lots of water in well drained soil.
If you want, you can propagate it c the cuttings left over.
Just chop them into two node cuttings and stick right side up.
Easy as pie to grow.