Well Big Boss is a Reality Game Show. There are two parts of this title: One is REALITY and the other is GAMESHOW.
First type of contestants are those that stick just to the first part of this title and live in the house just the same way as they live in reality. They don't play any game, make friends and enemies on the inner responses of likes and dislikes, and think that viewers will vote on the basis that how they are as human beings.
Second type of contestants completely sticks to the second part of title. They consider it a game that they have to won. They make their mind that no one in the house is their friend or enemy and they change their alliances and favors according to their changing interests and strategies. And they believe that viewers will choose the most sharp minded and smartest contestants as a winner.
Then there are third types of contestants who take both the parts of title. They use their mind, play games and have some strategy to win in their mind. But they don't forget their true self entirely and sometimes it is difficult to say that when they are playing games and why they are real.