Hi @shubhamverma27,
if all users are set in the same RoR block as kibana_access : rw , then yes, they can delete/overwrite dashboard of others.
also, in Documentation, there is a way to separate specific kibana indice per each user.
see here
@sscarduzio has in mind to work on something to finegrain access in indices in a future release, also in kibana.
I also provided a workaround here
this way keep the same indice, but work on rules and constraints.
you can see the 2 RoR blocks , and a policy definition has to be made regarding naming convention.