Theoritical Study is carried out on some of the Spinel compounds. These compounds have wide range applications in various optoelectronic devices, industries and ornamental purposes being natural gem stones. For the better performance and practical applications of these Spinel compounds the newly suggested approximation is used known as the "modified Becke-Johnson potential approximation (mBJ)" as presented in the Wien2K computer package which is commercially available. The optoelectronic responses of SnX2O4 (X= Mg, Zn), MgIn2O4, SiZn2O4, GeX2O4 (X= Mg, Cd) and CdX2O4 (X= In, Ga, Al) are calculated and presented. The calculated total and partial density of states of the studied compounds within only the mBJ approximation is a prototype since the patterns of the density of states for all approximations are almost similar to each other. In MgIn2O4 charge distribution between the cation and anions is uniform; hence the bonding nature is mainly covalent. Electron effective masses of CdX2O4 are calculated, CdGa2O4 has higher mobility of charge carriers as compared to CdAl2O4 and CdIn2O4. A unique character of cation replacement is observed in these compounds. If we replace the cation in all of the above studied compounds the band gap and its dependent optical parameters change which demonstrate the wide range applicability and appropriateness of these compounds in various optoelectronic instruments. All of the herein studied materials are found to have direct band gaps and hence most suitable for optoelectronic instruments.