@wiseranirudh can you try this?
std::wstring wstr = L"Hello world!";
wchar_t wcharArray[1024]; // Choose an appropriate size
wcscpy_s(wcharArray, wstr.c_str());
IChatMsgInfoBuilder* chatbuilder = meetingchatcontroller->GetChatMessageBuilder();
chatbuilder->SetReceiver(0);
chatbuilder->SetMessageType(SDKChatMessageType_To_All);
chatbuilder->SetContent(wcharArray);
chatbuilder->Build();
meetingchatcontroller->SendChatMsgTo(chatbuilder->Build());