Hi Gopabandhu
You would need to contact the SAP Education and Training Centre for the country as each country may have different rules.
However, my advise to you is to seek some form of training. I do realise India has specific rules but not sure on other countries.
As you are a maintenance engineer, I assume you are an end user and not necessarily configuring the system. Therefore, you may know your job quite well in terms of business processes but may not be strong on configuration of plant maintenance module.
Regards
Colleen