The principal reason why national, economic planning is still being pursued inspite of embracing a market economy since 1991 is that

Even after the 1991 liberalisation, national planning persisted chiefly because Five-Year Plans supply a coherent long-term perspective and strategic direction while accommodating market mechanisms. Post-1991 reforms shifted India from centralised to indicative planning, allowing Plans to guide policy, investment priorities and sectoral targets in a market-friendly way rather than replace markets [1]. The reform period (early 1990s) introduced liberalisation but retained planning instruments (including an annual plan phase) to manage transition and balance objectives like employment and regional balance [2]. Historically, Five-Year Plans have been the vehicle for setting national targets and coordinating public and private outlays, so they remain useful for macro guidance even in a liberalised economy [3].

Sources

1. [1] Indian Economy, Nitin Singhania .(ed 2nd 2021-22) > Chapter 6: Economic Planning in India > LPG (LIBERALISATION, PRIVATISATION AND GLOBALISATION) STRATEGY > p. 136
2. [2] Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 11: Industries > Eighth Five-Year Plan (1992–97) > p. 4
3. [3] Indian Economy, Nitin Singhania .(ed 2nd 2021-22) > Chapter 6: Economic Planning in India > ECONOMIC PLANNING IN INDIA > p. 131