Hello Nandakishor
It doesn't require any downtime(management and data plane are separate). You might need to however re-register your management tools once the IP change.
If you're unsure or uncertain reach out to support to help you.
The G350's have an IP for the SVP, and an IP for each controllers.
Here you can see the procedure to change the SVP IP:
https://docs.hitachivantara.com/r/en-us/service-processor/mk-97hm85049/changing-the-storage-ip-address
When you login to the Embedded UI(by accessing one of the IP's of the controller), you can set it in the maintenance utility:

You can then set the Controller IP's under Network Settings:

Best Regards
William
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William Jansen Van Nieuwenhuizen
Hitachi Vantara
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