@Sarah Mohd Nor Apologies for the delayed response. As far I am aware for integration of Cisco ISE with Entra ID it works with Microsoft Entra ID Free tier as well.
However after integration which features are you trying to leverage within Entra ID?
Please refer to these docs for type of features included in Entra ID Free/P1/P2
https://learn.microsoft.com/en-us/entra/identity/authentication/concept-mfa-licensing
https://www.microsoft.com/en-in/security/business/microsoft-entra-pricing
Let me know if this information helps to answer the above mentioned ask, if not feel free to post back.
Please remember to "Accept Answer" if answer helped, so that others in the community facing similar issues can easily find the solution.