The obliquity series used here (Laskar 1986) is valid only from about 8000 BCE to 12,000 CE, that is ±10,000 years from 2000. The year is limited to that range.
The Tropic of Cancer (कर्क रेखा, Kark Rekha) is the furthest north the Sun can stand overhead. That latitude equals the obliquity of the ecliptic: the angle between Earth's equator and the plane of its orbit, about 23.44° today. The Arctic Circle sits at 90° minus the same angle.
The obliquity is not constant. Tugs from the Moon, Sun and planets make it rock between roughly 22.1° and 24.5° over a cycle of about 41,000 years. It last peaked about 10,000 years ago and is now falling by about 0.47 arc-seconds a year, so the Tropic of Cancer moves south by about 14 m a year and the Arctic Circle north by the same amount. On top of that, nutation makes both wobble by up to about 9 arc-seconds (roughly 280 m) with an 18.6-year period; this page shows the mean value without it.
The values come from J. Laskar's 1986 polynomial for the mean obliquity (as given in Meeus, Astronomical Algorithms), which is accurate to about 0.01″ around 1000–3000 CE and to a few arc-seconds at the ends of its ±10,000-year range. Outside that range the polynomial is meaningless, so the page does not go there. Distances use the length of one degree of latitude on the WGS 84 ellipsoid at 23.4° (about 110.75 km).
Roadside "Tropic of Cancer" signs in Gujarat, Madhya Pradesh, Jharkhand, West Bengal and elsewhere were set up at different times and to different standards, and many mark a rounded value such as 23.5°. We have not plotted them because we could not verify their exact positions. Enter a sign's latitude in the box above to see how far it now lies from the line, and in which year the tropic passed it.