The question itself is vague enough that I'd say the first thing to do is check the source where you saw this claim. Financial news moves fast, and by September 2026 a listing that was being discussed months back might already be done, delayed, or completely off the table. If it's from a reputable business outlet, they should have named the company - that's basic reporting. The fact that the detail is fuzzy makes me suspicious it's either old news, speculation being treated as fact, or someone combining several different stories into one.
Given how many payment firms operate in India and how many are based in or connected to billionaire-backed conglomerates, you really do need the company name to get anywhere. Paytm had a rough IPO experience back in 2021, and since then the appetite for Indian fintech listings has shifted. PhonePe, owned by Flipkart/Walmart, has been valued incredibly high but tends to stay private. Jio Payment Systems or similar subsidiaries of larger groups pop up in discussions too. Without knowing which one you're actually asking about, any answer is just guessing.
My practical suggestion: search for the actual news article or press release with specifics. Use financial databases like Bloomberg, Reuters, or even the UK's FCA announcements if you want to know what's actually queued up for a London listing. Cross-reference with the company's own investor relations site or official statements. That'll tell you if something's genuinely happening now or if you've bumped into old speculation.