Just continue drawing the next joint, starting from the moving link of J1 to the next link. For 6 axis robot you will have 7 links and 6 joints in the end. All connected in a kinematic chain. To allow your robot inverse movement add base and tool frame to it. If you then test your robot and it doesn't move properly with robot jog, you probably made a mistake with your joint vectors.
Thank you GuidoDamm .yes i have done kinematics for Robot as you explained above ,this work only for if Robot J2 and J3 are independent joints.But in my case Robot has relation between joint 2 and joint 3.if i jog joint2 and joint3 values also will get changed.so i am looking for how to find relation between joint 2 and joint 3 for this Robot.