Given below are the full texts of the three Articles relevant to the current dispute between India and Canada. The link to the full text of the Convention follows at the end.
1.The receiving State may at any time and without having to explain its decision, notify the sending State that the head of the mission or any member of the diplomatic staff of the mission is persona non grata or that any other member of the staff of the mission is not acceptable. In any such case, the sending State shall, as appropriate, either recall the person concerned or terminate his functions with the mission. A person may be declared non grata or not acceptable before arriving in the territory of the receiving State
1.In the absence of specific agreement as to the size of the mission, the receiving State may require that the size of a mission be kept within limits considered by it to be reasonable and normal, having regard to circumstances and conditions in the receiving State and to the needs of the particular mission.
2.The receiving State may equally, within similar bounds and on a non-discriminatory basis, refuse to accept officials of a particular category
1.The premises of the mission shall be inviolable. The agents of the receiving State may not enter them, except with the consent of the head of the mission.
2.The receiving State is under a special duty to take all appropriate steps to protect the premises of the mission against any intrusion or damage and to prevent any disturbance of the peace of the mission or impairment of its dignity.
3.The premises of the mission, their furnishings and other property thereon and the means of transport of the mission shall be immune from search, requisition, attachment or execution.
Link to the full text: Vienna Convention on Diplomatic Relations, 1961 (unvienna.org)