I was trying to add a raster type data in my attribute but cannot find the 'raster' type data in the data type selection.
I'm using AGP 2.8.x and the Raster Field type is there for a new field. What release of AGP are you using?
Please ensure you are working on a Geodatabase Feature Class. Raster Field Type is not supported with Shapefiles.
You may convert your shapefile to a File Geodatabase Feature Class using Feature Class To Feature Class (Conversion)