gradient

hey is there any options to create gradient linear// radial ?

Not directly no. You can simulate gradients by generating a range of colors yourself. I've included an example here.

Was trying to do a circular gradient. but failure.
How to generate concentric circles?
How to give each circle a different color?
How do you get the smallest circle on top?

??

Here are some circular gradients. The big trick is to use a "reverse" node at the end to change the ordering, so the smallest circles are on top.