remote management issue?? from where can i get the username and password of remote management??

You need to Contact your Bank who are trying to install a remote management profile on your iPhone.

If You have an account with the Bank or you are an employee or a client then you may have received an email for activation. Look for the Username and Password in the email.

Contact the Bank for further details

If you are the owner or the owner has shared all information with you then to open Activation Lock:- If it is Activation locked, read here --> Turn off Activation Lock - Apple Support Activation Lock for iPhone, iPad, and iPod touch - Apple Support

Learn how to remove a device from a previous owner's account.

If you are not the owner and do not have the Apple ID and Password then there is no way that you can get into this iPhone unless the original owner shares the Apple ID and password with you. If you are lucky you can get into this iPhone if they (owner) accidentally remove the device from their apple ID.

Have you installed any remote management servers on your PC/Mac/iPhone ?

I am not sure what are you trying to attempt. Your Apple ID and password is what you need to use.

Remotely erase a device

To prevent anyone else from accessing the data on your missing device, you can erase it remotely. When you erase your device, all of your information (including credit, debit, or prepaid cards for Apple Pay) is deleted from the device, and you won't be able to find it using Find My:

1. Open the Find My app and tab the Devices tab.
2. Select the device you want to remotely erase.
3. Scroll down and choose Erase This Device.
4. Select Erase This [device].

After you erase a device, you can't track it. If you remove the device from your account after you erase it, Activation Lock will be turned off. This allows another person to turn on and use your device.

It would be better if you can please re-post with a screenshot, in order to understand the phenomenon better. Images / pictures speak louder than words. (Do not provide any personal credentials, such as email id, apple id, IMEI number, Serial Number, Phone number, if you are sharing a map ensure your location is not identifiable. etc)