Career

The salary of Mechanical Engineers depends on the type of industry and position of company. Normally a mechanical gets an average package of 30000 in starting. Also the scope in mechanical engineering is very good and one of the best career options to choose in engineering.

Hi Suman
Don't worry about your HSc Marks. Of course it is a good result , which comes under first class / division. So be confident and go ahead with your dream. Join for B Tech. It will never affect your placement.
All the Best

Of course,If the university is approved by UGC and Member of AIU.

Of course, you can practice as lawyer after B.Sc, LLB. You need to enroll with Bar Council of India as Lawyer after completing LLB. Also want to work a short period under a senior Lawyer as his junior for getting practical knowledge.
All the Best

To become Commercial Pilot, you should complete Commercial Pilot License (CPL)course. HSc with PCM is the eligibility criteria .Minimum 50% is mandatory.
It will take minimum one year to complete the program. CPL is focused on both theoretical and practical aspect. Theory is mainly deals with Flying Rules, Aviation rules and regulations, functions of various enginer parts and basic trouble shooting of Aircrafts, Airtraffic rules, Navigation system etc. It also requires 1000 Hours practical fly training.

in B.Sc there are many fields so first u decide in which field u r interested

Hi
You may check whether there is demand on the course you are taking or not and then decide.
http://www.sbs.com.au/yourlanguage/hindi/en/article/2016/05/17/want-migrate-australia-2016-17-skilled-occupations-list-sol-announced

You should opt for B.Tech in marine engineering.