I had hard time in performing these steps in the absence of Screen Shots, so thought of adding this post with Screen Shots.
A BI semantic model connection is created in SharePoint and provides redirection to business intelligence semantic model data in a PowerPivot workbook or Analysis Services tabular model database on a network server. Before you can create a BI semantic model connection in SharePoint, you must extend a document library to allow the creation of a .bism file. This step only needs to be performed once for each library, but you will need to repeat it for any library from which you want to create .bism files. Best practices recommend that you create a centralized library for storing .bism files so that you can manage permissions in one place.
If you already use SharePoint Data Connection Libraries, the BI Semantic Model Connection content type is automatically added to that library template. You can skip the steps in this section if you use a data connection library that already lets you create new BI semantic model connection documents.
You must have at least the Manage Lists permission to add and configure a content type. This permission is built into the Design permission level and above.
Click Yes and OK
On the same page under content type click
Add Different Content Types
To verify you added the content type, go back to the library and click New Document on the Documents area of the library ribbon. You should see BI Semantic Model Connection File in the New Documents list-
Click on BISM Connection - SSAS tabular Instance -
or you can use PowerPivot workbook
Workbook URL - http://localhost/PowerPivot Gallery/Book1.xlsx
Add a BI Semantic Model Connection Content Type to a Library (PowerPivot for SharePoint)
Good Blog, But my case , i could not see the "BISM Connection file" in the Business Intelligence content Types