we have a field with 3 drop-down options, if we create a ticket with one of the dropdown values the

[Chaitanya B]

Hi team,

we have a field with 3 drop-down options, if we create a ticket with one of the dropdown values then the ticket should only be visible to specified users/ group  

[Nic Brough -Adaptavist-]

You'll need to set up some form of automation that can use your field to decide on an issue security level to set.

See https://support.atlassian.com/jira-cloud-administration/docs/configure-issue-security-schemes/