Hey @poornakumar2542
You shouldn't need to touch the ISE side of the house. The FortiSwitch can be configured to act as a standard 802.1X authenticator.
Firstly, configure the RADIUS server settings to point at your ISE PSNs.
Then you need to enable 802.1X authN on the relevant switchports and make sure the relevant VLANs that ISE will assign have been configured.
You should also set up RADIUS accounting.
If you are trying to use Fortinet attributes (aka VSAs), you need to import the FortiGate VSAs from this link into ISE: https://community.fortinet.com/t5/FortiGate/Technical-Tip-Fortinet-s-RADIUS-Dictionary-and-VSAs-latest/ta-p/194896
If you just want standard 802.1X authN, that should all be up and running once you've set up the RADIUS settings on the FortiSwitch.
- BW
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