i am developing a BE final year project on Video Conferencing from Java with both unicasting and multicasting. I found there are some protocols such as SIP to implement it. are there any better and efficient way to implement it?

AFAIK SIP is concerned with establishing and controlling a session, but not with the actual streams of voice and video that are sent in the session. That would normally be the responsibility of the Real-time Transport Protocol (RTP/RTCP).
Maybe you are interested in researching innovative ways to achieve a breakthrough in video protocols, but if not, surely it's better to stick with standards that are supported in the largest number of clients?