Yes, you do require a visa to visit South Africa and the visa needs to be processed prior to your visit. The visa consulates for South Africa are in Delhi and Mumbai, you will have to complete your processes over there. In order to obtain your visa, you are required to have certain documents in hand such as: passport validation, tickets confirmation, stay confirmation, passport size photo etc. It is advisable to apply for the visa as early as possible as the time taken to process the visa depends. Moreover, the consulate/embassy decides on the sole discretion of your visa. There will also be a fee applicable that needs to be paid in cash.