where is the list for banks which available for connecting bank transactions?

Welcome to Quickbooks Community, Grace_287,

To check if your bank is integrated with Quickbooks Online is to go to your Banking tab and enter the name of your bank. Enter your bank's url, if the bank is not on the list, click on Request button and enter the name and url again of your bank then click on the Request button.  The request will be directed to our product engineers. However, we cannot guarantee that this will be added soon as it will be validated by our banking team and also needs approval from your bank if they allow any 3rd party integration. 

Hope this answers your question.  Feel free to reach out again if you have any other concerns.