At divine rank 200, you are a time lord (e.g. a monad), which is the highest rank where the template changes. Beyond that, you gain the template again - stacking it each time (e.g. a duad, triad, etc.) - for each additional 200 divine ranks you have, becoming a high lord.
At divine rank 1299, you've gotten enough quintessence to have the template six times, so you're a (comparatively weak) sextad.
Likewise, a time lord has a quintessence of 1,000,000,000,000,000 (one quadrillion) through 1,999,999,999,999,999. Each time their divine status increases (e.g. they gain the template again), the total amount of quintessence needed increases by the aforementioned amount (so a duad has two quadrillion plus quintessence, a triad has three quadrillion plus, etc.).
So your divine rank 1299 sextad has quintessence somewhere between 6,000,000,000,000,000 and 6,999,999,999,999,999.