Hello , I forgot the password of my Iphone. Is there any possibility to unlock it with the help of Icloud account?

The steps given in this link will help you reset the passcode -> If you forgot the passcode for your iPhone, iPad, or iPod touch, or your ...

If you do not remember the Apple ID Password then follow the steps given in this Apple Article -> If you forgot your Apple ID password - Apple Support

If you do not remember the Apple ID then follow the steps given in this Apple Article -> If you forgot your Apple ID - Apple Support

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.

https://support.apple.com/en-ie/HT204306

Step 1: Make sure that you have a computer (Mac or PC)

This process requires a Mac or PC. If you're using a PC, make sure that is has Windows 8 or later, and that iTunes is installed. You also need the cable that came with your iPhone, or another compatible cable, to connect your iPhone to the computer.

If you don't have a computer and you can't borrow one, you need to go to an Apple Retail Store or Apple Authorized Service Provider for help.

You can erase your phone from iCloud too but you will still loose data

No.