Yes, you can attempt your UP Board Class 12 exams in English even if you were admitted to a Hindi medium school.

The UP Board allows students to choose their preferred medium of instruction for the board exams, regardless of the medium of instruction in their school. This means that even if you were enrolled in a Hindi medium school, you can opt to take your exams in English.

However, it's important to inform your school about your choice well in advance so that they can provide you with the necessary resources and guidance for preparing in English. Additionally, you might need to submit any required documentation or forms to officially request a change in your medium of instruction.

To confirm the specific procedures and deadlines for changing your medium of instruction, it's advisable to contact the UP Board authorities or consult with your school's administration. They can provide you with the most accurate and up-to-date information regarding the process.