Hi @antonysanju37, thanks for posting on the forum and welcome to the SimScale Community 
It’s a bit hard to uderstand the exact problem you’re trying to simulate only by a written description. Could you provide some extra details and maybe a schematic of what you’re going for?
I’ll give you a general guideline on boundary conditions for FEA though:
- Clean your CAD: If necessary, clean your CAD so that it only contains the necessary details for simulation. (Documentation)
- Constrain your model: In reality, if stresses are being developed in a static scenario, your assembly needs to be constrained, i.e., there should be a reaction to the applied loads. The most common constraint would be a Fixed support.
- Apply loads: where are the loads applied in reality? You should apply the loads in the corresponding place in your simulation. You can do this by splitting a surface for instance so you can apply the load only on a portion of it.
Steps 2 and 3 are what we call boundary conditions.
Cheers
Igor