Plan seems to be Good. Which version of solaris will be on target.
Please refer MOS tech notes:
Database Preparation Guidelines for an E-Business Suite Release 12.2 Upgrade (Doc ID 1349240.1)
Complete Checklist to Upgrade the Database to 11gR2 using DBUA (Doc ID 870814.1)
R11i / R12: Oracle E-Business Suite Upgrades and Platform Migration (Doc ID 1377213.1)
R11i / R12 : Planning Your Oracle E-Business Suite (EBS) Upgrade from Release 11i to Release 12 (Doc ID 1406960.1)
Oracle E-Business Suite Release 12.2: Consolidated List of Patches and Technology Bug Fixes (Doc ID 1594274.1)
X A H E E R
Thanks a lot for your reply,the target Solaris version should be 6
Pls suggest us which one is easy method initially upgrade and finally migrate to Solaris or initially migrate and after upgrade to R12.2.3
Thanks In Advance
I would suggest you to upgrade first (if you have enough hardware resources) then migrate. Because as you have 188.8.131.52 and 10.2.0.4, you might get little support from Oracle if you face any issues.
More over with the latest versions, the migration process is simpler and easier.
If you do not have enough hardware resources then you please plan as ora_tech suggested.