Please help me guys if you have any knowledge about this topic.
You proceed to help yourself; afterwards, help will come from other sources. Please, start the job --
1. Collect 2 UNOs.
2. Collect 2 HC12 Modules.
3. Connect the modules with their respective UNOs as per instructions of this link.
4. Test the basic functionalities of these modules using the instructions of the above-mentioned link.
5. Now, you have in your hand 2 working HC12s.
6. Now, plan your project -- decide which module (HC12-A) will be collecting data from sensors, and these data will be transmitted to other UNO via HC12-B. Are you looking for Transmission/Reception routines? They will be come in into this Forum/Thread from various sources once you start the project and show your efforts.
The collective efforts of the Forum Members will make your project successful!!
(You may also visit this link for some idea on developing data communication routines between two HC12s.)