He made this remark while asserting that Britain is one of the most open and "incredibly welcoming" economies.
Addressing the staff of Hindustan Unilever (HUL) at the company's headquarters here, Cameron said: "Britain is an open economy and we encourage investments.... We should be having a conversation, which we will have with the Indian Government about opening up the Indian economy.
"Trying to make it easier to do business here, allowing insurance and banking companies to do more foreign direct investment into the Indian economy."
Britain is one of the most open, easy-to-invest in economies anywhere in the world, he said.
"We are incredibly welcoming. I am very proud of the fact that it is an Indian company, Tata, that makes Jaguars and Land Rovers that are taking the world by storm."
Tatas bought iconic car brands Jaguar and Land Rover, after the buyout of one of the largest British steel companies, Corus.
"There are still many rules and regulations in the Indian economy associated with how you did things in the past, which we think if you change will make your economy grow faster, will deliver more jobs, more wealth and more prosperity across your country," he said.
"So I it's a good conversation to have but it goes both ways. We should look at the things we need to do to take our barriers down and we hope that your government will do the same." he said.