Energy of nd level would be higher than \\\\((n+1)s\\\\).\\\\(nd=n+2\\\\), \\\\((n+1)s=n+1\\\\).So, electron will enter into lower energy level.i.e, \\\\((n+1)s\\\\)Let us take an example of \\\\('4p'\\\\) orbital. As per Moeller diagram, the orbital that will be filled after \\\\('4p'\\\\) orbital is \\\\('5s'\\\\). Hence, \\\\((n+1)s\\\\) orbital will be filled after \\\\('np'\\\\) orbital.