Can I go back to the college entrance examination where my hukou is?

According to the requirements of the college entrance examination, candidates must go back to their registered residence to register for the college entrance examination, which means you have to go back to Inner Mongolia to take the exam.

According to your situation, you should avoid the danger of being regarded as a "college entrance examination immigrant", that is, your household registration has moved to Inner Mongolia for more than 3 years before you can register for the college entrance examination.

Other than that, there won't be any problems.