Hello Nitin,
In order to increase our twitter follower find out the similar interest people and try following them.If they like your profile, they will surely follow you back.
And if you want to increase follower for your page, then find out the list of competitors and follow their followers.
All the above mentioned activities you can do it manually or use tools like DoesFollow,FollowCost,Twellow,Less Friends,Just Tweet It,Tweetadder
All you need to follow the people who are in the field of your niche. Like their, retweet their posts. All is need to have a healthy relation with them.