​@swanand m First, I will point out that as of this reply, the only way anyone can add content to a Miro boards is with Edit permissions, i.e., there is currently no role/permissions that only allow users to add/edit their own content. I did create a Wish List post around this for upvoting:

• New role: Contributor (can only edit their content)

Can I buy one Miro License and then add 50+ members to view the board or just add content to it?

Yes, you could either purchase a

• Starter Plan licence and use the Visitors feature to allow anyone with the link (no Miro account required) to edit the board/add content.
• Business Plan licence, and in addition to the Visitors feature, you would have access to the Guest editor feature which requires the user to have a Miro account, but is more secure as the link it not open to anyone with the link. You could also assign different permissions to different users, e.g., Bob can edit, but Jim can only view.
  • Note: With the Visitors feature, you can password protect the board.

More on Visitors, guests and members here.

Allowing full edit access, but stopping users from editing your content

You can also lock your content, so that visitors/guests cannot edit it.

NOTE: Guests can unlock, so you’d likely want to use the protected lock feature.