WHY THE RAM CONNECTION WITH IN STAADPRO. SHOW ME THIS PROBLEM?

If you are not using the STAINLESSSTEEL material you can just ignore it, or delete that material from your file in Modeling Mode under General - Materials. If you are using it you can specify these missing material properties also in Modeling Mode under General - Materials (assuming you are using STAAD.pro SELECTseries 6).

The message indicates that the values for the material properties is not set for Stainless steel. If you are using material Steel and NOT Stainless steel, you can simply ignore the message and proceed. As part of material definition in STAAD.Pro, these values are already included for any material that has been used in the model. For example here is a sample material definition in STAAD.Pro

For any material for which this has not been included, you can add these properties as part of the STAAD.Pro Material definition as shown below

For your information, these material properties are listed within the RAM Connection mode at the location below