In the extraction of which of the following, complex ion forms

Which of the following complex ions is octachedral ?

Which of the following complex ions is dimagnetic ?

Which of the following complex ions is diamagnetic ?

Which of the following complex ions has geometrical isomers?

In which of the following complex, the metal ion In which of the following complex, the metal ion t_(2g)^(0),e_(g)^(0) , configuration according to CFT

Which of the following ions can form complexes-