You don't get into the UNSC permanent membership just because you have a large population, and a supposedly large economy. You don't belong in that club. The 5 members have all fought in WWII, loss lives and defeated fascism. Some much more than others. Where was India during those times? It wasn't even a country when the UN was formed.
Indians might argue that it was the ROC, who originally sat on the China seat in the UNSC. But the ROC and PRC are two parts of the same China, and the vast majority of China is the PRC. Most of China chose the CPC over the KMT to rule the nation after WWII. China had lost around 20mil people in WWII, fighting Japanese fascism. India OTOH were either contributing Sepoy soldiers to the British, or colluding with the Axis powers. The ones fighting for the British did not fight for India, while the ones who fought for "Bharat" where on the same side as the fascists. So technically India (aka Bharat), cannot be allowed into the UNSC permanent members because it was an ally of the Axis powers.
The Big 5 must never let India get into the club. Because if they do, Japan, Germany, Italy, Spain, Indonesia, Nigeria, and others would have a right to demand for their own seats too. India has no place in the Big Boys club, and should be kept out of it.