Hi Mamata,
Could you please let us know more about how you plan to use Aether ? That will really help in answering your questions.
A block diagram showing how aether fits in your testing/solution will help our discussion.
Your 2nd question about 5G testing. Yes you can test most of the call flows using gNBSimulator. You can use gNBSimulator
as a standalone tool talking to any other Core Network or You can use gNBSim deployed next to SD-Core.
You can use the slack channel to send us queries.
Channel : aether-dev , sdcore-dev
Thank you
Ajay