The short answer is no, Oxford University is not older than the Aztec Empire.
Oxford University is said to have been established in the 12th century, with its teaching roots tracing back to around 1096. This makes it one of the oldest universities in the English-speaking world.
On the other hand, the Aztec Empire was founded much earlier, in the early 14th century, specifically in 1325 when the Aztecs settled in the area that is now Mexico City. However, the origins of the Aztec civilization can be traced back to the earlier Mexica people, who had settled in the region well before the founding of the empire.
Thus, while Oxford University has a long and rich history, the Aztec Empire’s establishment predates its founding by a couple of centuries, but importantly, the cultural roots of the Aztecs extend back to the earlier periods of Mesoamerican history. In summary, the Aztec Empire is historically older than the establishment of Oxford University.