Need help with creating a 2D polygon from a series of GameObjects in C#

Hi! I’m making a puzzle game about catching rain (circles) from the sky, and clicking the water to turn it into ice (a polygon). The only problem is that I’m a complete noob when it comes to programming with Unity and I only have a very basic understanding of it. I have absolutely no idea how to turn a whole bunch of GameObjects into a solid polygon and need help!! How can I make a script that turns a group of circles into 1 solid object with a click?

If you just want to group them together you simply have to generate a new GameObject and then set the parent of each rain drops transform.

GameObject newParent = new GameObject ();
foreach(transform t in raindrops)
    t.parent = newParent.transform;

Where raindrops is an array of the transforms of each raindrop.
Edit: I misunderstood the question. Completely different answer than the original.

@rbeldessi answer is actually correct. When you parent all your objects to one game objects, you can then treat that parent as your main object. What you may want to do is, after parenting remove all Rigidbodies from your little objects and add a rigidbody to the parent. Colliders on children objects are ok, they will work normally and they will raise events you can catch in parent scripts.

The other biggest challenge I can’t wrap my head around is that when you click on 1 drop it should also affect all drops it’s connected to. Though thanks a lot for helping to answer!!!