How can i build loving lasting relationship with my six year old. he does not want to go anywhere with me but spend all time with his father?

Decrease pressure: 6 year olds don't have any expectations regarding relationships. They just do what they like at the moment. It's very possible that he feels completely secure and loved in his relationship with you and now wants to build that same feeling with his dad. Stop pressuring him or the expectations of what he should or shouldn't do - kids sense that pressure and it is a turn off. He really does love you!

Focus on quality: Your son has different needs for both parents. At 6 yrs, he is probably more interested in the outside world where physical action, sport etc would be more fun. After talking with Dad, make a weekly activity chart with roles assigned, including some bed time ritual. Display chart at a prominent place. The key in dealing with children behavior issues is in being consistent with a united front.