Two things - the bottle and the product.
For the bottle, the base markings could very well suggest a mid 1960s date but not necessarily. The letter I in a circle is for the bottle manufacturer which is Owens-Illinois.
As for the product, you will find this page interesting: https://www.firstversions.com/2016/07/jose-cuervo.html The adverts shown on this page suggest that by the 1960s that Cuervo was already using square clear bottles. Will be hard to learn more without finding a labeled example of your bottle.
Chris
