The verb here would be to do, so did is the past participle you would use here. However, as comments have pointed out, research is an uncountable noun so you would not do a marketing research but would do marketing research.
Also, typically research into the state of a market, which is what sounds like you are saying would be called market research rather than marketing research.
Marketing research may discuss the activities or methods of a company's marketing department, marketing or advertising methods or alternatives,how to sell something, advertising choices, etc.
Market research may discuss what people are buying, what products exist (or not), if there may be a demand for a product, what gaps exist in the market, etc.