While checking MOS i found an interesting note (ID 964976.1) which states:
Applying a kernel patch or a Solaris patch bundle is not the equivalent to installing the specific Solaris 10 "update 6" image. 11gR2 RDBMS software is only certified for a base install image of Solaris 10 update 6 or greater.
There is a FAQ (ID 971464.1) on this problem. Here it states:
Oracle/Sun has specifically started that "installing patches will not bring it to Update 6".
It is only certified for a base install image of Solaris 10 Update 6 or greater, or an upgraded image of an earlier Solaris 10 update to at least Update 6 or greater. There are only two methods to accomplish this " image". Please see Question #9 for more details.
So keep this in mind when installing 11g R2 on Solaris SPARC.