Hi @Subodh
Thanks for posting your questions!
For your 1st scenario, I recommend using the Age interval. See documentation about interval dimensions here and how to import them Data from Jira
Here you can also see and example report already made for the unresolved issues by age - Unresolved issues by age interval and priority
For second scenario - It looks like the community post here - Open Issues measure - #2 by martins.vanags is the solution you are looking for!
Best wishes,
Elita from support@eazybi.com