I have chronic partial acl+pcl tear+laxity(50 days delayayed treatment). it has been 8 months can it be treated 100% with surgery/reconstruction.

Yes-reconstruction: Multiligamentous knee injuries are more difficult from both a technical and rehabilitation standpoint. Untreated chronic injuries of this type increase the degree of difficulty even more. The status of the articular cartilage & meniscii are critical variables affecting overall functional recovery too. A thorough examination/consultation by a sports medicine orthopaedic surgeon is necessary now.

Yes and no: Surgery is always iffy & is forever. There are world class soccer players playing with acl ruptures. They made dedicated efforts to develop strong muscles of upper & lower leg. Physical therapist can be helpful in this. The principle is when a joint is loose, the way to accommodate is to develop "gorilla" muscles around joint so that muscles take over what damaged ligaments can no longer do.