When  ${\text{N}}_2^{+}$ is formed from ${\text{N}}_2$ the bond order

If one electron is removed from the bonding orbital of ${\text{N}}_2$ molecule, then ${\text{N}}_2^{+}$ ion is formed. As per M.O theory if the electrons are removed from  bonding  orbital then the bond order is decreased. Since the formula used to find bond order in a molecule or ion is as below:

$\text{Bond order = }\frac{1}{2}\times ({\text{N}}_{\text{b}}-{\text{N}}_{\text{a}})$

From the above formula,  if ${\text{N}}_{\text{b}}<{\text{N}}_{\text{a}}$ then the bond order is decreased.