In Jain dharma, coconut is not inherently forbidden.

• If you are not fasting, coconut is generally acceptable.
• If you are observing upvas, ekasana, ayambil, or any vrat on Chaudas, then whether you may eat coconut depends on the exact vow and your tradition.
• In strict fasting, coconut should not be eaten.

So the simple answer is: yes, if you are not under a fasting restriction; no, if your Chaudas vrat does not allow it.