In which company I should invest today: BSE or NSE?

Did you mean through which exchange: NSE or BSE? 


BSE has many more companies listed on it than NSE. But most of the actively traded companies are listed on both the exchanges. 

So unless you want to invest in a company only listed on BSE, you can choose either. It won't make difference. 

Also, most borkers will be members of both the exchanges. You can technically decide to even buy from one exchange and sell from the other. 

Hope this helps. All the best!