Total sale for 5 months = ₹ (6435 + 6927 + 6855 + 7230 + 6562)
= ₹ 34009.
Total sale required fro average to be ₹ 6500 = 6500 x 6
= ₹39000
Required sale = ₹ (39000 - 34009)
= ₹4991