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Please find the below MOS documents :
Things to check before upgrade to 184.108.40.206 (Doc ID 1363369.1)
Things to Consider Before Upgrading to 220.127.116.11 Grid Infrastructure (Doc ID 1312225.1)
Oracle Clusterware (formerly CRS) Rolling Upgrades (Doc ID 338706.1)
18.104.22.168 Patchset Location For Grid Infrastructure And RDBMS. (Doc ID 1362393.1)
RACcheck 22.214.171.124 Upgrade Readiness Assessment (Doc ID 1457357.1)