Don't ever buy penny stocks just because they are cheap. And always stay away from circuit stocks. Once they hit upper circuit they will keep hitting upper circuit and you'll not able to sell on 5-10-15-20-50-100% profits but when they start lower circuit you won't be able to sell either. And at last you'll sell on dirt price.
Below 50 you can add nhpc and forget for next 10 years. Your stock will multiply 10 times in 10 years. And it's not a company which will close overnight.