What is the ruling of Sharia on continuing studies in non-Muslim lands if the father desires that, while the son wishes to return to Muslim lands?

Obeying parents is obligatory except in sin. Residing in non-Muslim countries is, in principle, not permissible, except out of necessity or severe need, while distinguishing between non-Muslim countries based on the prevalence of evil deeds.

If you fear falling into evil deeds, then you are not obliged to obey your father in residing in a non-Muslim country, and you must return to your country. However, if you feel secure concerning yourself and your religion, and what you are studying is needed by Muslims and is not available in your country, then continue your studies while preserving your religion and maintaining contact with Islamic centers.