Ans: Investing Rs 5 lacs in single stock provided your total allocation to this single stock dont exceed more than 3 to 5 percent of total Equity portfolio than its fine otherwise you are taking excessive risk on the same and should move towards diversified Equity mutual funds to take exposure. But if you have existing portfolio and you want to allocate 3 to 5 % in single stock than you can look at defence & aerospace sector theme and select market leader from the same.

I hope this will help

Disclaimer: This information is just for educational purpose and not a buy or sell recommendation.