Thanks for the co-operation has been given by you over the past years.
Is this correct? till now they are providing support to us...
but i have mentioned as "over the past years"
so is it correct to use present perfect continuous tense or past simple?
Your sentence is not correct.
If you wish to use a passive sentence, you would have to say:
"Thanks for the co-operation that has been given by you over the past years."
But that seems unnecessarily awkward.
Why not just say,
"Thanks for your cooperation over the past years."?