Hello Aspirant,

They are two different domains of engineering with ample scope and opportunities. Below I have listed the scope of both courses:
Scope of Aerospace Engineering:

Job Roles:

Team Leader - Aerospace CS

Engineering Manager - Filtration
Engineer - Manufacturing Engineering
Development Engineer - Industrial Engineering
Engineer - Technical Publication
Design Engineer- Reverse Engineering for Aerospace
Product sales Engineer - B.E (Mechanical, Aerospace, Aviation)
Engineer - Sensor Engineering

Hiring Companies:

Hindustan Aeronautics Ltd (HAL)
Indian Space Research Organisation (ISRO)
National Aeronautical Lab (NAL)
Airline companies such as Indian Airlines, Spicejet
Defense Research and Development Organisation (DRDO) etc

Scope of Biotechnology:
Any student who is contemplating on pursuing a career in Biotechnology must be aware that this field is still developing in India. Therefore, the number of job openings and pay packages are both very low when compared with IT and CS fields. Since the number of job openings is very less in Biotechnology, the number of companies coming for placements will be very less. Also, core companies only hire students from universities such as IITs, NITs etc. If your university is not reputed nationally or state wise, chances of any biotech or pharmaceutical company coming for placements sessions will be impossible.

Hope this helps

Thank you