Concept of coding a win condition for a linking game (not asking for code)

Hi Im still new to unity and Im trying to learn by making games that has already existed. Basically im making a 2d game where you have to connect a puzzle of a eg.4x4 grid and you have to click on the grid to rotate the shape so that it fits and form a complete circuit the grid is generated by a script which uses prefabs that i have created before hand. sorry if i phrase my sentence wrongly or unclear