The preamble of Indian Constitution reads:
"WE, THE PEOPLE OF INDIA, having solemnly resolved to constitute India into a SOVEREIGN SOCIALIST SECULAR DEMOCRATIC REPUBLIC, and to secure to all its citizens:
JUSTICE, social, economic and political;
LIBERTY of thought, expression, belief, faith and worship;
EQUALITY of status and of opportunity;
and to promote among them all
FRATERNITY assuring the dignity of the individual and the unity and integrity of the Nation;
IN OUR CONSTITUENT ASSEMBLY this twenty-sixth day of November, 1949, do HEREBY ADOPT, ENACT AND GIVE TO OURSELVES THIS CONSTITUTION."
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"Socialism" is a dirty word these days... At least among the upward-mobile, urban, literate (educated?), Indian middle class... And many bemoan the "socialism" (which, by a leap of/across logic, gets automatically equated with dictatorship, corruption, inefficiency, stagnation, etc.), and how it kept the country - notwithstanding its history and point of reference - from miraculously transfoming into something like South Korea, Japan, China (despite its being the highest in terms of income disparities), or even USA (...or at least like the top 5% of that country)!!
In any case, interestingly, the 1949 Indian Consitution does not proclaim that India is "socialist" country... that the new independent India opted to be a "socialist" country is actually a myth!!!
The original Constitution of India - as can be seen below - says: "We THE PEOPLE OF INDIA, having solumnly resolved to constitute India into a SOVEREIGN DEMOCRATIC REPUBLIC.... Nothing about being a "socialist" country

Nehru, himself, was in favour of a mixed economy. In 1956, he said (I think when the Industrial Policy Resolution was ratified):
"
I think it is advantageous for the public sector to have a competitive private sector to keep it up to the mark... I feel that, if the private sector... is abolished completely, there is a risk of the public sector becoming slow, not having that urge and push behind it."
So when did India become a "Socialist" country?Actually, almost 3 decades later - and more than a decade after Nehru's death!!!
The two additional words
"SOCIALIST" and "SECULAR" were added to the Indian Constitution by the controversial 42nd Amendment, by Indira Gandhi
in 1976, during the Emergency,
and came into effect on January 3, 1977.
...Just a bit of historical trivia!!
Previous in the series:(1) The Story of Junagadh (2)The Foundations of "Nehruvian Socialism"(3) A "Nation-in-Making", and
(4) Legacy of "The Raj"