First and foremost, congratulations on achieving a good rank in CUSAT. You can get any branch in SOE, other than CS or Safety and Fire Engineering. In case you wish to go to CUCEK, you’ll get any branch at that campus.
However, SOE offers much more facilities and exposure in comparison to CUCEK. I would recommend you choose your branch after thorough consideration.
Congratulations on getting such a good rank. I have many friends who cleared CUSAT and are well settled in their respective fields. Based on their reviews about the institution, I can give you some information about it a bit.
In short, 1,820 is quite a good rank for CUSAT if you are into any field except CSE and Safety & Fire. Nevertheless, if you are looking for these specific branches, you can most likely get into these at CUCEK.