Why there is not leverage provided for every stock listed in NSE and BSE?

when we go for finding leveraging provided for the stocks, we not get the all stocks listed in the exchanges are not provided leverage by the broker. why is this so?

Providing a leverage and allowing a trader to trade on a stock for the amount more than his actual capital is risky for the trader and that person can actually loose all his capital. So to minimise the risk broker allow leverage on the stock where volatility is reasonable for them.

is the stocks list for leverage decided by exchange or broker

The list for leverage is decided by the broker

It is decided by broker, because broker is the one who is letting you take leveraged position. So Broker is also on risk when he provide leverage to user. So broker decide based on his risk management, how much leverage is to be provided and on which stocks.