The IPO grey market is an over-the-counter market. It requires a local dealer, someone you know already or find a connection with.
The best way to find someone who deals in the IPO grey market is to look for a local dealer who does 'Dabba Trading'. They are present all cities and towns. Most Dabba trading dealers does deal in IPO grey market transaction or they could point you to the dealer who does it.
Dabba trading is an illigal business that runs parallel to the government approved exchanges (BSE, NSE and MCX). In this, all transactions are done in cash (mostly with black money). The transaction cost far less in comparison to trading at BSE, NSE, or MCX. All the transactions are closed by end of the day and settled in cash. They are popular in Rajasthan and Gujrat.
Dabba Trading and IPO Grey Market transactions are illigal and highly risky. In the case when somthing goes wrong, there is no body who can help you.