Recently Sundeep contacted me when he was trying to install 11gR2 and the runInstaller gave failed message for 4 OS patches.
I went through 11gR2 install guide for Solaris SPARC (64-bit) available on http://download.oracle.com/docs/cd/E11882_01/install.112/e10863/toc.htm#i1011296.  
In our environment, we are on correct Solaris patchset. However, these 4 patches are required in addition to being on the current patchset:
4.1 Operating System Requirements
The following are the operating system requirements for Oracle Database 11g Release 2 (11.2):
Solaris 10 U6 (5.10-2008.10)
To determine the distribution and version of Solaris installed, enter the following command:
# uname -r
5.10
In this example, the version shown is Solaris 10 (5.10). If necessary, refer to your operating system documentation for information about upgrading the operating system.
To determine the update level of Solaris installed, enter the following command:
$ cat /etc/release
                      Solaris 10 10/08 s10s_u6wos_07b SPARC
           Copyright 2008 Sun Microsystems, Inc.  All Rights Reserved.
                        Use is subject to license terms.
                            Assembled 27 October 2008
4.2 Package Requirements
The following packages (or later versions) are required for Oracle Database 11g Release 2 (11.2):
SUNWarc
SUNWbtool
SUNWhea
SUNWlibC
SUNWlibm
SUNWlibms
SUNWsprot
SUNWtoo
SUNWi1of
SUNWi1cs
SUNWi15cs
SUNWxwfnt
SUNWcsl
119963-14 or later (SunOS 5.10: Shared library patch for C++)
120753-06 or later (SunOS 5.10: Microtasking libraries (libmtsk) patch)
139574-03 or later (SunOS 5.10)
The following patch is optional and may be required depending on your needs:
124861-15 or later (SunOS 5.10 Compiler Common patch for Sun C C++)
You may also require additional font packages for Java, depending on your locale. Refer to the following Web site for more information:
http://java.sun.com/j2se/1.4.2/font-requirements.html
To determine whether the required packages are installed, enter commands similar to the following:
$  pkginfo -i SUNWarc SUNWbtool SUNWhea SUNWlibc SUNWlibms SUNWsprot \
  SUNWtoo SUNWi1of SUNWi1cs SUNWi15cs SUNWxwfnt
system      SUNWarc   Lint Libraries (usr)
system      SUNWbtool CCS tools bundled with SunOS
system      SUNWhea   SunOS Header Files
system      SUNWi15cs X11 ISO8859-15 Codeset Support
system      SUNWi1cs  X11 ISO8859-1 Codeset Support
system      SUNWi1of  ISO-8859-1 (Latin-1) Optional Fonts
system      SUNWlibms Math & Microtasking Libraries (Usr)
system      SUNWsprot Solaris Bundled tools
system      SUNWtoo   Programming Tools
system      SUNWxwfnt X Window System platform required fonts
ERROR: information for "SUNWlibc" was not found
If a package is not installed, then install it. Refer to your operating system or software documentation for information about installing packages.
4.3 Compiler Requirements
Sun One Studio 12 (C and C++ 5.9) is supported with Pro*C/C++, Oracle Call Interface, Oracle C++ Call Interface, and Oracle XML Developer's Kit (XDK) for Oracle Database 11g Release 2.
Make sure that the above are installed on your Solaris 10 box before installing 11gR2.