If you want to retain the mechanical - field, it would be better on your part to fill the gap with some assignment fitting to mechanical jobs such as Lathe - industry, Paints - industry or any job of maintenance in the Industries like Cement, Oils, Power - plants, Heavy - industry etc.
The employers would like to see you with a vast - experience in your field so that they offer you higher - assignments on the basis of your accumulated experience.
CAD/ CAM are the jobs related to Mechanical but there is as an application of the soft- ware system. You may acquire such certifications while retaining your Mechanical - field.
The other option could be to shift your job - profile altogether with the joining of MNC in a software field. If you do have interest for it, go in for strengthening your basics and communication - skill. This will help you in clearing the multiple rounds of the Intervies being conducted by MNC and your final selection would be possible with your presence of mind and the precise responses to the queries asked by the members on the Interview - board.