Hi @Hari Shankar
The ROPC flow is a silent login flow that authenticates by hardcoding username/password and will be blocked at login if your users have MFA enabled.
The flow suitable for authenticating users who have enabled MFA is auth code flow, because the auth code flow is an interactive login flow, which logs in users through browser interaction.
Hope this helps.
If the reply is helpful, please click Accept Answer and kindly upvote it. If you have additional questions about this answer, please click Comment.