India?
3 requirements for any member of P5, simples:
1. Historically independent superpower (either regional or worldwide)
China - the Middle Kingdom: Qin, Han, Tang, Song, Yuan, Ming, Qing
US: 20th century
UK: 17th-18th-19th-20th century: industrial revolution...
France:17th-18th-19th-20th century: Napoleon...
Russia: 17th-18th-19th-20th century: Tsars...the Soviets
Independent superpower means: regional/global tenological superpower, at least a regional military superpower, single independent kingdom/nation/country with strong nationalism, large territory*, (relatively) large population.
(*France and the UK proper are small, but each of them used to have a huge overseas empire prior to WW2)
2. independent allied regional superpower at the time of WW2.
The US, the UK and China were the original P3 of the UN - allied powers.
Russia and France joined soon after the WW2.
The US aside, all of them were amongst the strongest Eurasia powers at WW2.
China's contribution to WW2 is largely underestimated by the currect cold-war-oriented Western media, but not at a time of the war though. The entire allied powers reckoned that China was the main power resisting Japanese aggressions in the Eastern Eurasia for the most part of WW2.
3. current regional/global superpower
Amongst top economical, technological and militarily the most powerful in the world.
Economial: GDP size, a key position in the global manufactoring value chains, a top position on world-wide import & export, with a strong and widely used currency in global trade and finance.
Technolgical: independently-owned high tech knowhow (not accquired by importing) reflected by total sum of WIPO patents worldwide, with fundamental science researches amongst world-leading powers, with independent (or key-role of a team) manned space launches, a top position in all major industries in the world, a key source of world's technological goods import...
Militarily: able to manufacture indepedently, whenever required, most if not all of basic and advanced weaponaries (advanced Aegis destroyers or the equivalents, >= 4 gen warplanes HELOs, new gen army tanks, aircaft carriers etc with all the key subsystems such as electronics, radars, and missiles... thermonuclear weapons, ICBM, SSBN...), amonst world's leading export powers,
Japan and Germany don't fit into Requirement 1 for the most part, and definitely not Requirement 2.
India doesn't fit in all 1 , 2 and 3.
Needless to say that
ALL P5 members were originated, and are located, in the high altitude northern hemisphere,
with average IQ of the populations = or > 100.
India? not then, not now, not even in 57th century.