Anoop, hi.
We just went through a license renewal, and I can confirm that. You do not need any additional VPC's for the MQ instance installed with ACE. You can also use that MQ instance for anything else you might require.
IBM uses Virtual Processing Units (VPC's) to "count" licenses. You can buy a bucket of VPC's and then slice and dice that bucket depending on your requirements.
For ACE the breakdown of VPC's to Physical cores are:
1 physical core = 3 VPC's in production & 2 physical cores = 3 VPC's in non-production.
So if you plan to install, as an example, dev (2 cores), qa (2 Cores) and prod (4 cores) you would need 3 + 3 + 12 = 18 VPC's.
I hope that makes sense.
Rodney