The concept of cost to company was created first to show the total cost of employment and then used to make employees believe that are getting more than they actually are.
Your employment Co tract, or appointment letter would specify your remuneration. If it says xyz amount is your cost to comoany, or it says that the remuneration is on CTC basis, then they have provided adequate disclosure. It’s just that your gross earnings are much lower than you thought it was. But in such cases you should have asked and clarified what CTC is and how it affects your take home pay