thanks for the suggestion. my problem is resolved.... I have studied theBI Data Modeling guide and findout that i have to create a data model that can have multiple data sets. after that i create data model in BI Publisher with mutiple data sets and then i create a template in word in online mode. and because im working in online mode i have access to all data sets of my data model. and this problem is resolved.
Now I have another problem.... my ultimate target is to develop reports for Apex with dynamic behaviour. after developing the template i upload it to apex in Report Layout shared compnent and it work fine for hardcode query.
I dont know how to pass parameters to Report Query at runtime. i tried to make a where clasue like WHERE REQ_ID = :REQ_ID. but it did not work. can you or anybody who reading this help me how to do this in apex.