I feel like Avni will discover that Mukku is a boy and she will make the connection that way and try to expose Kalyani. I don't think she will figure out that Mukku is Moksh.
When she exposes Kalyani, I feel Kalyani will confess that this is Moksh and she will tell Malhar what happened that day. The doctor has already confirmed that Moksh was kidnapped by Ahir, so I think Malhar will defiantly investigate further with Kalyani, hence the nok jhok like you said. I think the investigation will lead to Avni.
I am just going by the general THR trend here, but there are clear patterns:
1. Deshmukhs and Ranes have always fought and reconciled. So they always need a reason to reconcile. If Swara is really dead due to this domestic abuse by Vivek and AS, the Deshmukhs and Ranes can never, ever reconcile. HarThak cannot forgive this.
HarThak forgave AS for the Sampu thing as that was not really her fault. Yes, she got Sampu married to Malhar but she never meant to scam Malhar.
The same thing with Malhar's mother and RS's death, it was tit for tat, so both forgave each other. Same Nal and Baapji's death - both were accidents.
The outlier here is Swara's death. HarThak cannot forgive Deshmkhs for this if Swara is really dead.
2. New villain always enters at the end of the previous track. So anytime now, the new entry should be making an appearance and should be fitting into the current track. Since most of us here think that Avni and Ahir's deaths are interrelated, I feel the new entry is related to Swara. Unless CVS relates new entry back to Avni. Maybe this will be Avni's partner that has some dushmani with the Ranes. Kind of like Sampu and Rachit.