Find the like term of 3xy².

Let us check each option one by one.

Option A:

The expressions 3xy² and x²y have the same variables but have different powers. So, 3xy² and x²y are not like terms.

Option B:

The expressions 3xy² and 3x²y² have the same variables but have different powers. So, 3xy² and 3x²y² are not like terms.

Option C:

The expressions 3xy² and 2y²x have the same variables with the same powers. So, 3xy² and 2y²x are like terms.

Option D:

The expressions 3xy² and 6xy have the same variables but have different powers. So, 3xy² and 6xy are not like terms.

Hence, 2y²x is the correct alternative.