Hi Brahmaiah,
have you tried to use the search function? There are quite some documents available on SCN on this topic. For example have a look at the following two documents:
Creating a Custom Genil/Bol object Model
Extend BOL Model BT with custom table type relationship - CRM - SCN Wiki
Especially the latter seems to describe the exact problem you are trying to solve.
By the way, the pointers provided by Thea refer to Web Service consumption in SAP CRM. IMHO these are not useful to solve your requirement.
Best,
Christian