All year, the same gap
Neither Tokyo nor India changes its clocks, so the gap is the same on every date. IST here means India Standard Time.
12:00 PM Wednesday 15 Jul in Tokyo is 8:30 AM Wednesday 15 Jul in India (IST, 3 h 30 min behind).
Why daylight saving conversions need a date explains skipped and repeated clock readings. The rules here come from the browser’s time zone data and can lag a government change.