do you have a hardcoded ip address?
which os do you have by the way?
The error is due to the fact that there is another system on the sify network is having the same ip address. Each computer on the network has to have a unique ip. Since yours is trying to duplicate the ip, your box doesn't connect on the network. If you ip is not being assigned dynamically, or even if it is, you may need to contact customer care and tell them your problem. They will be giving you instructions.