Statement I is correct: It has frequently been argued that reservation is contrary to efficiency and merit. Even the Supreme Court of India appeared to have agreed with this argument in some of its judgments, holding that Article 335 mention of the term efficiency of administration will limit the scope of Article 16(4) provision for reservation in services. 

Statement II is incorrect: Article 335 of the Constitution of India states that the claims of the members of the Scheduled Castes and the Scheduled Tribes shall be taken into consideration, consistently with the maintenance of efficiency of administration, in the making of appointments to services and posts in connection with the affairs of the Union or of a State. 

Article 335 of the Indian Constitution only mentions the efficiency of administration and does not define the same.