Hi Shwetha,
In-order to stop SLA timer on any status of the ticket.
We have got the following option in the status menu:
1) Administration > Requests/Incidents/Problems > Status
2) Open any status (For e.g hold status)
In this we have option called Stop Service Type Events and Targets which has to be checked inorder to stop the SLA timer.
Below is the screenshot for your reference:
I hope this answers to your question.
Thanks
Junaid