Question

Right so i got some plants in my tank (been in about week and a half) some are dropping roots, is the normal, what should i do ?

Yes it's normal. Leave them be.
Some say that they are rooting because their isn't enough nutrients in the water column therefore the roots are sent out to look for nutrients in the substrate.
Any signs of plant deficiencies then just up the nutrients.

My elodea densa does that, but i could swear its when it grows a new stem thing. Once its grown you cut it off and replant into substarte.