I download ise2.1 from cisco website and has evaluation license 90 days .and now we need to buy license ...should also buy ise 2.1 or just license like base/plus/apex.
You need both the endpoint licenses (base/plus/apex) and one ISE license for each virtual appliance you install. You probably want to install at least two for availability.
More information is found in the ISE ordering guide:
