I recommend against getting a bird if your parents themselves are against having a bird. The only reason birds at my house have been able to live at my house happily is because my parents were bird people since before I was born. There are sacrifices they are willing to make (such as household aesthetic) that other parents would not be.
Ex: Weather suddenly turned to Fall weather yesterday, it was chilly. My mom immediately made space for him in another room, as the room he lived in throughout summer became chilly and having him there, esp w/ the regular baths that he requires, would essentially be a death sentence. I have seen parents dismiss these sorts of things because rearranging the house for the bird is an inconvenience, and they feel that animals are "just" animals. It seems like a small thing (moving the cage, not that it would be a death sentence), but these sorts of minor things will have a negative effect on your parents' view on the bird which they will just see as a burden and it will just make everyone unhappy. There are a lot of lifestyle adjustments and contributions which need to be made to keep a bird content.
Also THE ATTENTION commitment is HUGE. I live with 5 other people and we all play/spend time with Fajr directly after coming home (and washing our hands

). The only time he spends in his cage is when guests are over, and when we're all out of the house. When we first got him, leaving him alone for even a few minutes was almost impossible, as he would become frantic.
GCC's have a pretty long lifespan, and college is a thing that does come about. With your parents not agreeing to this, you have no guarantee that your bird is going to have a home once you leave for college. You might give it to a friend to take care of, but one thing I have learned is that you can never trust a person to take good care of a bird. You'd need to find someone who is experienced with birds, and even then they might have incorrect ideas about bird care and would most likely brush off all of the instructions that you had given them.
I know I sound preachy, but as someone who started convincing her parents to buy her animals at the age of 12, I'm trying to warn you off of my mistakes. Pets that your parents do not love or care for will not be happy in your home and that was a major factor for me whenever I considered getting an animal and worked on persuading my parents.
I don't want to leave you completely without hope, and so I will give you a tip in finding a pet that your parents will see the reason in:
Instead of looking for a pet which you feel is the most entertaining and wonderful, try looking for a pet which which best fits your lifestyle first and narrow it down from there. Know the amount of time you spend at home (outside of doing homework/chores) and instead of thinking about how great the pet will be for you, think about how great you will have to be for the pet to consistently be happy.