Will it be possible to connect the Mac Mini to the MacBook Pro and use the laptop's screen, keyboard for working on Mac Mini?
Physically through a HDMI cable this isn't possible.
The MacBook Pro cannot take display input, only output.
This goes for any HDMI devices, not just a Mac Mini. You couldn't run a PS4 on your MBP screen for example.
The only way it might be possible is by sharing the screen in a method such as this.
I connect from my 15” macbookpro to my mac mini via connect to server & sharescreen, then do all that is necessary : install software, play videos via iTunes which are then shown on the Samsung tv via hdmi from the mac mini - then log out leaving iTunes and the video playing fine...
No special third party software needed - all native by apple...