I have created 6 invoice template with different bank information but quickbooks don't keep seperate. it makes all template information same. how to keep it different?

Hello there, elias-gazi93. 

I'd like to clarify how and where you entered the bank detail information on the Invoice template so I can walk you through the detailed steps. The same bank information will show if we enter it on the template's Email and Message to customer on section. 

We can use the Add footer text field so the bank information won't change. I'll show you how: 

1. Log in to QuickBooks Online. 
2. Go to the Gear icon and select Custom Form Styles. 
3. Click on the first invoice template to edit.
4. Select the Content tab and click on the Footer section of the sample. 
5. Enter the bank information for this template and then click Save. 

Do the same thing for the next 5 invoice templates. In addition, let's make sure that we select the correct template before we send out invoices. Here's how to select a template on the Invoice page. 

1. Open an existing invoice.
2. At the bottom, click Customise.
3. Select the correct template for the invoice.

For more details with customising your sales forms, check out this article: Customise invoices, estimates, and sales receipts in QuickBooks Online. 

I'll be here if you need anything else. You take care always and have a great day!

Thanks for your valuable solution