The contact could have been as little as a few stranded people and animals reaching miraculously the South American shores, it could have been regular trade with the two peoples aware of each other and their geographies, maybe even diplomatic missions, or anything in between, can we say with any confidence the degree of this contact?
You might be interested in some of the posts in this response from the FAQ in which I cover some of this topic.
The TLDR is that yes contact definitely occurred-- chicken bone evidence is still debated, but the origins of the sweet potato in South America and its prevalence across Polynesia along with the word for sweet potato in most Polynesian languages being a loan word from South American Quechua indicates yes contact and exchange did take place at least once. Since the word and the crop both went out into the Pacific together, facilitating settlement on places like Aotearoa where the tropical agricultural toolkit of Polynesian navigators well less suited, we can be pretty sure that contact/exchange involved dialogue to some extent.
Was this contact sustained? That is harder to say. Certainly at least one voyage took place and while there are linguistic and archeological hints that more maybe have taken place, a lot of that is still debated and the subject of ongoing research.