The basics of cancellation process is simple enough; transmit signals to cancel out the radar waves. But for this to work, one needs to have knowledge of the exact frequency the enemy ground radars are transmitting. This is further complicated when the AESA comes into play. So the cancellation could work only for ground-based radars and then only with the necessary information.
Therefore the Rafale relies more on RCS reduction and even though both Rafale and EF claim to have the third lowest RCS after the F-22 and F-35 respectively, it is commonly believed that the Rafale beats the EF in this respect.
However the EF's overall performance is better esp. with more thrust and a higher ceiling than its counterpart. The EF has also entered service with more AFs than the Rafale.
The Rafale on the other hand has offered ToT and this is one area that India is definitely interested in.