Commercial-off-the-shelf (COTS) component selection is considered a critical task in effectively developing a component-based software system (CBSS). COTS vendor selection involves selecting the right vendors who can provide reliable COTS components at a suitable price and on time. However, COTS vendor selection is commonly a multi-criteria decision-making (MCDM) issue” associated with many paradoxical criteria for which the decision maker’s knowledge may be uncertain and ambiguous. This paper attempts to present “Intuitionistic Fuzzy Sets (IFS) combined with the technique for order preference by similarity to an ideal solution (TOPSIS) method” to appraise and choose the best COTS vendor under the environment of group decision-making while considering reliability, delivery time, compatibility, vendor support and functionality as benefit criteria. In contrast, price and maintenance are the cost criteria. The considered case study demonstrated the presented case effectively.