Trade barrier are rules and regulations that regulates foreign trade.
Indian government put barriers to foreign trade after independence because of the following reasons
(i) To protect the domestic producers within the country from foreign competition.
(ii) The competition from importers would have crippled the new born industries of India.
In such a situation, imports of only such commodities were allowed which were quite necessary such as machinery, fertilisers, petroleum etc.
(iii) During 1950s and 60s, competition from imports was giving a death'blow to growing industries in India.