Can Anyone Suggest me a method to Upload PST to Exchange Server

Yes, there are manual methods and automated-tools to upload PST to Exchange Server.

If you are in search of manual techniques then, you can follow the below mentioned steps to easily import PST files into Exchange Server. The methods are mentioned below:
1. Creation of EXUtil$ Shared Folder
2. Managing Uploading Permissions
3. And then Uploading PST

Please let me know if you will be able to migrate or not.

I am briefing Step 3.
1. Choose the desired mailbox and click … icon and then choose Import PST option.
2. Then specify the location of Shared folder created and then click Next.
3. Specify the Mailbox which will receive the contents and then click Next.
4. At the final page, we are asked to send email to one or more users. So, as to confirms the users that now they can access the data.
You can also visit here to get detailed overview and description of the steps.

Also, I want to remove the duplicate PST contacts while uploading them to the Exchange Server.