What is better to control diabeties, oral drug or injectable insulin?

They both: Work. Best is diet and exercise, plus whatever medication your doctor thinks is appropriate for your particular case of diabetes. There are also non-insulin injectable medications known as glp-1 agonists which are often helpful. Either of these choices, or more often a combination of several, can control you blood sugar if done correctly.

Depends: If oral drugs work then why take insulin. If the oral drugs do not work then you have no choice but to take insulin.