The emergence of generative artificial intelligence (GenAI) and its applicability within higher education institutions (HEIs) has gained momentum worldwide. GenAI tools have caused a paradigm shift in education including students’ research activities. Despite various studies being conducted on GenAI tools in education, most research remains concentrated on developed countries, with limited attention to how these technologies are perceived in developing nations. Therefore, this study explores the usage and perceptions of GenAI tools among postgraduate students enrolled for postgraduate diplomas, honours and master’s degrees at a private HEI in South Africa. Using a mixed-methods approach, the study surveyed 75 students to understand their usage and perceptions of GenAI tools for supporting research activities. The findings reveal that almost three-quarters of the students use GenAI tools, particularly ChatGPT, and have a positive attitude towards the use of GenAI tools to support their research activities. The high usage of GenAI tools is attributed to their capability to generate research ideas, summarise articles, and simplify difficult concepts. Over a quarter of the surveyed students do not use GenAI tools due to concerns about plagiarism, bias, privacy and the potential to impair cognitive development. 78% of the students are familiar with the institution's policy on GenAI. Most students use GenAI tools to generate research topics and ideas. HEIs should assert balance in integrating GenAI tools to support students’ research activities. HEIs should further invest in universal frameworks that will serve as guidelines for using GenAI tools in scholarly activities without violating academic and ethical integrity.