The possessive adjective "its" would have the plural "their" or "theirs". Neither uses an apostrophe.
Example : "The cat ate its food. The dogs ate their food."
Example: "The car was theirs."
The plural possessive of "its" is "their."
Singular possessive: secretary's Plural: secretaries Plural possessive: secretaries'
The plural is lads. The plural possessive is lads'.
The plural is relatives. The plural possessive is relatives'.
The plural form is Mexicans. The plural possessive is Mexicans'.
The plural possessive of stepsister is stepsisters'.
The plural form is echoes. The plural possessive is echoes'.
The plural form is Mexicans. The plural possessive is Mexicans'.
Coaster's is singular possessive. The plural is coasters, the plural possessive is coasters'.
The plural of senior is seniors. The plural possessive of seniors is seniors'
The singular possessive of "ant" is "ant's" and the plural possessive is "ants'".
The plural is briefs. The plural possessive is briefs'.
The plural is lads. The plural possessive is lads'.
The plural is trollies. The plural possessive is trollies'.
The plural is stations. The plural possessive is stations'.
The plural is relatives. The plural possessive is relatives'.
The correct form is "its" for the possessive form in the plural. "Its" is used for both the singular and plural possessive forms, without an apostrophe.
Museum is singular. Museum's is singular possessive. Museums is plural. Museums' is plural possessive.