The number of isoelectronic species among Sc³⁺, Cr²⁺, Mn³⁺, Co³⁺ and Fe³⁺ is 'n'. If 'n' moles of AgCl is formed during the reaction of complex with formula CoCl₃(en)₂NH₃ with excess of AgNO₃ solution, then the number of electrons present in the t_2g orbital of the complex is _______.