Earlier innovation studies perceived open innovation to be associated with large organisations, but it is becoming relevant to small and medium-sized organisations due to global competition and turbulent market conditions. Open Innovation (OI) model combines external knowledge with internal knowledge by facilitating purposive inflows and outflows of knowledge. The success of open innovation model is dependent on organisations' interaction with other organisations. Literature highlights the location importance and organisation size in enabling interactions among participants and promoting collaboration. This paper presents the results of a survey conducted among Indian IT organisations within and outside the IT cluster on open innovation practices. The results indicate that the organisations in a cluster are ahead in terms of open innovation activities. This study reveals the differences among small, medium and large IT organisations in relation to open innovation practices.