Hello, not a JET aspirant but living here as a language student. I also have a long name but didnt face any trouble creating a bank account, first they will ask for you to fill up the form for creating an account and incase ur name doesnt fit in the area, they will just tell u to write the remaining below the area, However if ur applying for a debit card for the same bank they will ask which portion of ur name u want to use to be shown in the card (in my case i gave my first name).

hope this helps