Is board resolution is sufficient to sell assets of pvt ltd

i am planning to purchase a land which is in the name of a Pvt Ltd and this Pvt Ltd is issued a board resolution signed by directors and mentioning a Mr X to excute sale of the land. is this sufficient or Power of attorney is required. Board resolution is not a registered not even noterised and only on comapny letterhead signed by both directors and Mr X.

Thanks & regards