Registration of a travel company

The smallest option is Proprietorship concern. or you can run on your own name also. For both of this you need to have a trade license initially from the local corporation or municipality or panchayet. Then open a current account in the name of your company/individual.

and so on you grow your liability increases

Rightly advised by Advocate Raja, follow what he says. Only one problem may arise that your house may fall in the category of commercial and there may be impact on the Tax structure. Some residential areas are also not allowed for commercial business.