Hi Kalyan,
Take a look to the next link (announcement letter), ordering information section:
IBM WebSphere Application Server V8.5 delivers a faster, more flexible development environment along with new intelligent management capabilities for enhanced resiliency
http://www-01.ibm.com/common/ssi/cgi-bin/ssialias?subtype=ca&infotype=an&appname=iSource&supplier=897&letternum=ENUS212-109#h2-ordinfx
IBM has different ways to license. And price depend on the customer (small, medium,...)
In this link (contact us for pricing) you can talk with and IBM representative to get requiered information
https://www.ibm.com/marketplace/cloud/application-server-on-cloud/purchase/us/en-us
Hopet his helps. Tell us if you need more support.
Regards