You will need to upgrade to get certification configuration. And the first Peopletools release certified with WebSphere 8.5 is... Peopletools 8.53, not older than a week.
But, Peopletools 8.53 is not certified with CRM8.9...
So, question : what's the need for this upgrade ?
we have a separate project going on , upgrade of websphere from 6.1 to 8.5 in all applications which are using 6.1. , can you help me what are the compatiable Wepsphere version with pt849 and any suggestion for my current situation?
You are already using the only WebSphere version certified within Peopletools 8.49.
The only way to go on WEbSphere 8.5 is an upgrade of your application (9.0) as well an upgrade of your Peopletools (8.53).
To be honest, managing such upgrade can be painful just because of the WebSphere upgrade across all your env., unless you are planning for several weeks of works and have the budget for this.