Hi @Madala Chaitanya Kumar 

Starting from Paris Multi Row Variable set variables are accessible in Flow Designer. How you will be doing this is clearly mentioned in thread below:

https://community.servicenow.com/community?id=community_question&sys_id=9957d7cadb3fdc903daa1ea668961966

If you prior to Paris version then you need to have a look at below threads:

https://community.servicenow.com/community?id=community_question&sys_id=e4f5ffb0db40e8d0190b1ea668961933

https://community.servicenow.com/community?id=community_question&sys_id=0500bc19dbc8338ca39a0b55ca961908&view_source=searchResult

Hope this helps. Please mark the answer as correct/helpful based on impact.

Regards,
Shloke