There is not much difference between OPC and Private Limited. In OPC the control over management, profits and losses of company is with one person however in a company there are more than one. It is basically useful for small companies having paid up capital of less than Rs. 50 lakhs. However if the limit is extended then the OPC has to invariably file forms with the ROC for conversion in to a Private or Public Company, with in a period of 6 months on breaching the above threshold limits.
You can register your OPC with the help of Legistify.com by clicking on the link below: