Can a memo be included in the managerOffer operation. I tried to include a memo in my manageoffer transaction but it did not go thru.
The memo is part of the transaction, it's never part of an operation. You can set a memo in any transaction no matter what kind of operations it contains, so a transaction with a memo and a manageOffer operation should work fine.
You will find the reason for transaction failure in the horizon.submitTransaction calls response. It can be a bit tricky to decode it (server response is json, contains a
result_xdr which is a base64 + XDR encoded object and not all sdks have intuitive methods for accessing that), feel free to open another question if you struggle with that.