It seems to be debated that Buddha was born around 583 BCE. This led me to question what other philosophers that were alive during that time had to say about him and his followers if any? Is there any documentation or factual evidence that any prominent philosophers knew about him at the time? As well as wrote comments about him or his teachings?
Did anyone publicly debate his teachings that weren’t from India? Or visited temples and speculated on him and his followers. I am basically asking for current speculations of that time. What was the general consensus of him outside of India during that venture or close years around his popularity?
wrote comments about him or his teachings?
It is important to understand that India at the time of the Buddha was not a literate society. The "teachings of the Buddha", the teachings of other ascetic religions and the even the Upanishads either didn't exist yet or were oral traditions during the era in which the historical Buddha was alive.
With a few dubious exceptions, the earliest examples of writing we have in India are the Ashokan pillars from the mid 3rd century BC which is probably at least 150 years after the Buddha passed away. Its still some hundreds of years after that before manuscripts of Upanishads, buddhist texts and Jain texts were created.
Even in these later texts I am not aware of any non-Buddhist references of the Buddha. There is no direct evidence that the buddha existed until we get to the Ashokan pillars. The earliest indirect evidence that he existed is that there was temple type activity at the site of his Awakening built soon after his death or even possibly during his lifetime.