The starting position at ISRO as a scientist/engineer is called ‘Scientist-Engineer- /SC’. This is the post that you will join after completing your bachelor’s or master’s (after giving the ICRB exams).
The starting basic salary is 56100 INR. Over this basic salary, there is Dearness allowance (which is 0% at the moment), which increases every 6 months or one year by 7%.
In addition, you will be given appropriate House rent allowance (HRA) and Travel allowance (TA), which varies from city to city depending on which class of city you work in. HRA can be 10–20% of your basic salary depending on the city (so, can be up to 11,000 for cities like Bangalore). Same goes with TA.
So after adding these things you will get around 70,000 INR per month.
In addition to this, you will get around 25,000 INR every six months as a bonus, and around 15,000 INR per year as update allowance.
Over this, you will get a Leave travel concession (LTC) every year to travel to your home town or some specific place in India along with all your dependent family members. This provides you flight tickets once an year to travel around India or to your home town. There are many rules for LTC, which you might find online.
Every year, there is 3% increase in your basic salary, irrespective of your performance.
Every 4 years, you will called for a promotional interview (this depends on your performance). If you play your cards right, and perform well in interview, you can get up to 18% of raise in you basic salary, if you get the promotion.
So all things considered, working for ISRO is a pretty good deal.