Rahul,
Welcome to InidiaWilds!

You need to tell us if you know what kind of photography you want to do? Whether you want to start with bird photography, mammal photography, landscape etc has an important bearing. However, most of us start our photography and then later on realise where our heart lies. So I would say that the EF-s 55-250mm lens is a good lens to start your photography. Try to understand it and then as and when you feel more confident, and sure about the direction you want to take, and then you can decide on your next purchase.

Please check the others section to get some ideas about the excellent use of this lens by Dr Hari in capturing vine snake.

Cheers,
Sabyasachi