Hi @Uday Shankar
From my research, it seems there is no way to set the initial password complexity when creating a new user via the Users navigation bar, it defaults to setting the initial password complexity to Simple.
If you want to customize the user's initial password complexity, then you can try creating an Azure AD B2C local user using user flow/custom policy.
After creating the sign up/sign in flow, go to Azure AD B2C > User flows > Find the sign up/sign in flow you created > Click "Properties" and you will be able to configure the user initial password complexity.
Hope this helps.
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