Maternal leave

Sir I was on leave from Feb 2108 to July 2018 as I was due date was March 2018. But after joining I extended my leave till March 2019. Both these leaves were accepted by management . Then when in April I had to join I got a telephonic call to join in sep 2019 as the syllabus of that session was over and my service was not required for that time period . I resumed my duty in September and served till December when the management told me to leave in dec . They told that they going to release salary of nov and dec after my resignation only . The nov cheque was dated 12/12/2019 but I recived my nov cheque on17/01/2020 only . Dec and nov salary credited both injan only to my bank account . My maternal salary they didn’t cleared for 6 months and told me to write full and final settlement . They have given me internal clearance certificate , my relieving and my experience certificate also . I stay in shimla so I moved back here after my resignation . I send them legal notice claiming my 6 months salary in return they have demanded a 3 month salary in lue of my notice period as in resignation letter I wrote immediate effect . So what should be the course of action . As one lawyer I consulted told me that I can file a case in shimla but olawyer is saying that I can file a case from place I was working .