Jawaharlal Nehru University Delhi Answered Questions

No, it is not necessary. Candidate must have obtained a Bachelors degree under 10+2+3 pattern of education in Physical, Biological, Agricultural, Veterinary and Fishery Sciences or Pharmacy or Engineering/Technology or 4-years B.Sc. (Physician Assistant Course) or M.B.B.S. or B.D.S. degree from any recognized university.
Details :
https://www.shiksha.com/science/course/m-sc-in-biotechnology-jawaharlal-nehru-university-mehrauli-delhi-9950

For JNU M.Sc Environmental Science, we need to go through all these topics and books thoroughly:
1. Question paper solved for 5 years
2. Chemistry 10+2 organic and physical
3. NCERT Biology 10+2 PT
4. Biology (Nitrogen Dioxide) read this chapter
5. Ecology (Book) by Mr. P.D Sharma
6. Math - Matrix chapter
7. Physics 10+2 2.
The exam is in objective-type, so referring solved objective type guides will also help you. Currently, there are no solved question papers of JNUMSC Environmental Sciences. UGC Solved Question Papers also will be a great help for you. But don't depend merely on solved question papers as the questions may be changed every year.
Boltin Keller and Tyler Miller are established writers in the field. Refer any one of their books.
hope this helps

No, you can't get direct admission for Japanese hons in JNU because admission process is by entrance test mode then there will be merit screening.
You can get the further info from below given link:
https://www.shiksha.com/humanities-social-sciences/languages/course/b-a-hons-in-japanese-jawaharlal-nehru-university-mehrauli-delhi-268867
The Entrance Test Online Application Available on the Official Website of Jawaharlal Nehru University. Application form for all courses is issued from 15th September 2017.
Hope this helps.

MSC Physics Entrance Exam Syllabus:
Simple Harmonic Motion
Doppler effect
Diode and triode valves
Electromagnetism and magnetism
Thermometry
Archimedes principle
Capacity and condenser
Elasticity surface tension
Photometry
Photo-electric effect
Chemical effect of current and thermo-electricity
Gravitation
Nuclear structure and nuclear energy
Reflection at plane and spherical surface
Refraction through spherical surface
Kinetic theory of gases
Eye optical instrument aberration and defect of vision
Atomic models and spectra
Transmission of heat
X-rays
Work power and Energy
Electric field and potential
Thermodynamics
Adiabatic changes
Semi-conducting devices
Alternating current
Universe
Refraction at plane surface
Wave nature of light
Electromagnetic induction
Isothermal changes
Expansion of solids, liquids and gases
Rotatory motion of rigid bodies
Cathode rays and positive rays
Viscosity and Bernoullis principle
Calorimetry
Motion in one, two and three dimension
Radio-activity
Electric conduction and heating effect of current
Matter waves
Uniform circulation motion
Simple circuits
Wave motion
Superposition of waves (beats, interference and stationary waves)
Vibration of columns and strings
Solids
Newtons law of motion
Hope this helps.

Yes, I think you are eligible because JNU conducts the admission through entrance mode:
Further details you can get from below given link:
https://www.shiksha.com/humanities-social-sciences/geography/course/m-a-in-geography-jawaharlal-nehru-university-mehrauli-delhi-268822
Its syllabus is almost same as that of undergraduate (honours) in geography. Just go through its syllabus which is available there on internet. Go through the question papers of past years to get an idea what kind of questions will be asked and then start preparing accordingly.
Entrance test consists of 100 marks. 60+40. Where 60 marks are for objective questions of one mark each. Subjective questions are of 40 marks. Practice maps and diagrams to score well.
Hope this helps.