Hi
i hope you need cross selling for Third party scenario with Item category TAS
if so, when ever you maintain condition records in VB41, check cross selling delivery control which should be Blank
and in item category determination check whether
Cross selling is active for TAS
you have to check for your order type+item category group+CS01 ( item usage)+ TAS(higher level item category)
if this combination is available Cross selling materials will determine
if you are getting any particular error, please provide the error for further analysis
regards,
santosh