Air Hostess

Yes, you can still try for air hostess job. All you need to do is appear for the interview.

There is no such key metrics that can be followed. The only thing required is pursuing the course efficiently and acquiring the best skills to get an edge over others.

You can not pursue a postgraduate before completing a graduation course.

Yes, hopefully. Most of the airlines ask for 160 cm. You should be able to go for it.

Between 5 feet, 2 inches and 6 feet, 2 inches. However, this may vary airline to airline.

For becoming a cabin crew, the minimum height for female candidates is 157 cms and your height is 5ft which corresponds to 152cms.
Hence, I'm afraid you might not be in a position to apply for Cabin Crew profile. There are some relaxations although for those who belong to Northeastern parts of India.
You will have to check that with the airlines itself. It is mentioned in the recruitment advertisement!

Most of the airlines conduct walk-in interviews. Keep checking the career page of the respective airline's website. They periodically update vacancies there only.

Eligibility Criteria:
Good in spoken English
18-26 years of age.
10+2 with a degree in hospitality, or another graduate degree.
Height: A minimum of 155 centimetres, weight proportionate to the height for girls.
Height: A minimum of 170 centimetres, weight proportionate to the height for boys.
Eligible for an Indian passport.
Unmarried
Perfect eyesight
Good health
Clear complexion