Answer is **9 Clubs**

Column wise:

7Spades+10Heart=17(as 17 is more than 13 so, 10Heart-7Spades=3hearts

2Clubs + 4 Clubs = 6 Clubs(as 6 is less then 13)

8heart + 4heart = 12heart

13Diamond + 2Clubs= 15 (as 15 is more than 13) so, 13 Diamonds-2Clubs = 11diamonds

6 heart + 8 spades = 14, so 8spades -6hearts = 2 spades

Thus,

**4 Clubs + 5 Clubs = 9 Clubs.**