What course will be the best for the high-paid salary is relative because it depends on different interests, skills, and career goals. However, some fields have always been offering high-paid jobs; those include:

Tech-Related Fields
Computer Science Engineering: In this field, one can do software development, data science, AI, or cybersecurity. Information Technology: Network engineering, cybersecurity, and software development.
Data Science and Analytics: it's a highly in-demand field as more and more data are being generated.
Healthcare:
Medicine (MBBS) : The medical degree is generally a respected profession that has high earning potential.
Dentistry: Dental surgeons have high demand for their services, especially in urban areas.
Pharmacy: Pharmacists have a huge role in healthcare and are paid highly competitive salaries.
Finance and Management:

Chartered Accountancy (CA): A highly respected profession with great career opportunities.   MBA (Master of Business Administration): An MBA can lead you to various high-paid jobs in management and business.   Remember:

Passion and Interest: In a field that truly interests you; this is where you will be able to sustain motivation and display performance towards the best you can do .
Skill Development: Keep your skills updated and in pace with the recent trend.
Networking: Developing professional relationships will make you climb through your career ladder.
Devotion and Hard Work: Success in any field cannot be ensured unless achieved through devotion and hard work.
Even though these fields offer high-value job opportunities, experience, expertise, and the post which is applied for also decide the salary.