Is it possible to assign CA from both FDD and TDD in the same site for particular user?

Dear Experts,
Is it possible to assign CA from both FDD and TDD in the same site for particular user?

It is, but combinations are limited and mostly FDD is PCell.
Although standards do allow TDD as PCell as well.

Yes correct.
One is Pcc and Others are Scc.
If any sites is having both FDD and TDD is available.
That case how will be configured to the users.
But network is assigned one Pcc at that time?
Which one will be priority?

For attaining the max throughput FDD would be priority!
What about TDD In that case?

If FDD is Pcc, Uplink coverage is better than TDD is Pcc, cell edge user throughput is improved.

Ok. It has assigned based on coverage or user traffic?
What about Downlink end?
And what is the role of Scc?

Will It be assigned from FDD or TDD?
If its is based in coverage perspective.

In DL CA, Scc is just for sending DL data to UE. Uplink, UE only send data via Pcc only.

If TDD has more Rx than FDD, uplink TDD coverage may be better than FDD due to Receive diversity, so in this case TDD can be the Pcc.
I think main idea is to select which band has better UL coverage, it should be Pcc.
Moreover, for UE sides, firstly FDD-TDD CA UE just support FDD as Pcc, but later some UE chipset also support TDD as Pcc.

It can be. One site with 02 baseband processing board, 01 FDD baseband + 01 TDD baseband.