My contract did say that I will need to wear clothes as per company
If it is in the clause of the contract, it shouldn't have been taken lightly because like your boss said why did I accept the job in the first place if I am not comfortable with this. but you can always see what that certain clause says, does it say revealing, open, short, tight or elegant? from there you take on the below advice (if you prefer)
Now, if we talk about the mentality of south Asian people (and no offense to any) they have a strong opinion "If it shows, it will sell" and that has sadly been objectified it into women because you know the reason. In your situation which might tick your boss off if pushed because he can say it was in the clause, but as a man perspective (me), you can dress well. Revealing clothes isn't always a "deal maker".
Is there a way to reject wearing those types of clothes and keep my
job at the same time?
You can/might turn this around by dressing more elegant, look for good premium dresses, good salon for good haircut and taken professional makeup classes on youtube, this (might) will change the mind of your boss from "open" clothes, but if he insists, it is a sign that says that he is trying to sell his business by objectifying a women which might not be ok with you or other women.
The above assumption is based on if I was a boss and I had a secretary, I would rather ask for to dress more elegantly, executively and premium, if I had to ask my secretary to wear revealing clothes, then it is my thought process that is wrong and if things might go beyond business with secretaries (it is in history).