The Government of India has enacted the Micro, Small and Medium Enterprises Development (MSMED) Act, 2006 in terms of which the definition of micro, small and medium enterprises is as under:

Enterprises engaged in the manufacture or production, processing or preservation of goods as specified below.
A micro enterprise is an enterprise where investment in plant and machinery does not exceed Rs. 25 lakh;
A small enterprise is an enterprise where the investment in plant and machinery is more than Rs. 25 lakh but does not exceed Rs. 5 crore;
A medium enterprise is an enterprise where the investment in plant and machinery is more than Rs.5 crore but does not exceed Rs.10 crore. In case       of the above enterprises, investment in plant and machinery is the original cost excluding land and building and the items specified by the Ministry       of Small Scale Industries vide its notification S.O.1722(E) dated October 5, 2006.
Enterprises engaged in providing or rendering of services and whose investment in equipment (original cost excluding land and building and       furniture, fittings and other items not directly related to the service rendered or as may be notified under the MSMED Act, 2006 are specified       below.
A micro enterprise is an enterprise where the investment in equipment does not exceed Rs. 10 lakh;
A small enterprise is an enterprise where the investment in equipment is more than Rs.10 lakh but does not exceed Rs. 2 crore;
A medium enterprise is an enterprise where the investment in equipment is more than Rs. 2 crore but does not exceed Rs. 5 crore.