Yes, you can register for the CA Foundation Exam if you have completed Class 12 from an international education board.

In order to register for the CA Foundation Exam, you need to fulfill certain eligibility criteria set by the Institute of Chartered Accountants of India (ICAI). One of the eligibility criteria is the educational qualification, which requires you to have completed Class 12 or its equivalent from a recognized board or institution. This means that if you have completed Class 12 from an international education board, you are eligible to register for the CA Foundation Exam. Here are the detailed steps to register for the exam:

Step 1: Obtain the required documents
- You will need to obtain the following documents before starting the registration process:
- Class 10 mark sheet or its equivalent as a proof of date of birth
- Class 12 mark sheet or its equivalent as a proof of educational qualification
- A recent passport-sized photograph
- Scanned copy of your signature
- Proof of nationality, such as a copy of your passport or Aadhaar card

Step 2: Create an account on the ICAI website
- Visit the ICAI website and create an account by providing your personal details, email address, and mobile number.

Step 3: Fill in the registration form
- Log in to your account and fill in the registration form with the required details, including your educational qualifications, address, and other personal information.

Step 4: Submit the required documents and pay the registration fee
- Upload the scanned copies of the required documents, including your Class 10 and Class 12 mark sheets, photograph, signature, and proof of nationality.
- Pay the registration fee online using a debit/credit card or net banking.

Step 5: Verify your registration
- After submitting the registration form and fee, your application will be verified by the ICAI. This may take a few days.

Step 6: Receive your registration letter and study material
- Once your registration is approved, you will receive a registration letter and study material from the ICAI at your registered address.

Step 7: Prepare for the CA Foundation Exam
- Start preparing for the CA Foundation Exam using the study material provided by the ICAI and other relevant resources.

Step 8: Book your exam
- After preparing for the exam, you can book your exam slots through the ICAI website.

Step 9: Take the CA Foundation Exam
- On the scheduled date and time, appear for the CA Foundation Exam at the designated exam center.

Step 10: Check your result
- After the exam, you can check your result on the ICAI website.

Note: It is important to regularly check the ICAI website or official notifications for any updates or changes in the registration process or eligibility criteria.