Is it permissible to enroll in a study program affiliated with a usurious bank, with the intention of later working for an Islamic finance company that is a subsidiary of it, and to receive a salary from the bank during the study period?

It is permissible to work for companies affiliated with usurious banks if they are financially independent and adhere to Islamic law; otherwise, it is not. It appears that the contract here is for work at a usurious bank, and work at the Islamic finance company is not primary. Therefore, it is not permissible to enter into this program unless the contract is specifically for work at the Islamic finance company. As for the salary from the bank during the study period, this falls under dealing with someone whose wealth is predominantly unlawful.