mac address/Wifi connection

Afternoon

I would like find out if it is possible for someone to hack my whatsapp conversations and calls via wifi connection? If its possible how can i prevent the person from looking into my conversation now .

WhatsApp uses end-to-end encryption, so you’re basically safe.
Even if an attacker captures your raw data stream of a conversation, they still have to decrypt it. I wouldn’t say that it’s impossible, but frankly not within reasonable amount of labor, time and skills.
Assuming that your WiFi is already protected and encrypted with WPA2/aes, there’s the next layer of encryption to mess with.
When entering paranoia-mode, you can open a IKEv2 vpn tunnel from your phone over the encrypted WiFi to tunnel the encrypted WhatsApp conversation through…

With this being said - what’s the relation to MikroTik/routerOS?

-Chris