How to find time if the body acceleration , mass and tension with which it is pulled given?

Answer 1

Now wait a minute.
If you know the acceleration, you knew the mass and tension because
a = Tension/mass
if you know a:
v = initial speed + a t= Vi + a t
x = initial x + Vi t + (1/2) a t^2

in the lucky case that initial speed and initial displacement are zero:
v = a t and x = (1/2) a t^2