Gallium-68 ($T_{1/2} = 68$ min, $I_{\beta+} = 89%$) is an important positron-emitting radionuclide for positron emission tomography and used in nuclear medicine for diagnosing tumours. This study gives a suitable reaction to produce ⁶⁸Ga. Gallium-68 excitation function via ⁶⁸Zn$(p, n)$ ⁶⁸Ga, ⁶⁸Zn$(d, 2n)$ ⁶⁸Ga, ⁷⁰Zn$(p, 3n)$ ⁶⁸Ga and ⁶⁵Cu$(\alpha, n)$ ⁶⁸Ga reactions were calculated by ALICE-91 and TALYS-1.0 codes. The calculated excitation function of ⁶⁸Zn$(p, n)$ ⁶⁸Ga reaction was compared with the reported measurement and evaluations. Requisite thickness of the targets was obtained by SRIM code for each reaction. The ⁶⁸Ga production yield was evaluated using excitation function and stopping power.