Colleges in Thanjavur

Hi, that is an impressive rank! You'll get seat in both the courses with your rank. But choosing your branch should be based on your interests. If you are into how millions of megabits of data is transmitted across the world and if you want to know how your calls are getting connected to someone on the other side of the globe, ECE is your forte. If you want to learn about heat engines, working of a motor engine and stuff like that, mechanical engineering is your cup of tea.
Remember to always choose your branch out of your interests and not based on other things like placements and stuff.
All the best!

JEE Mains marks are also important criteria. If you have more than 105 marks in JEE Mains then you can get admission.

No, you'll not be able to get a seat in SASTRA University for your rank. Try in some other colleges. It's not the end of the world.

No, information and technology is a very much sought after field in SASTRA University and the seats will be done a long before you'll get to choose. Try your luck with information and communication technology.

1800 is a decent rank. You'll be able to choose from a handful of courses like electronics and instrumentation engineering, chemical engineering, biotechnology, bio informatics and aerospace engineering.
This does not include the five years integrated M.Tech program. I wouldn't recommend that to anyone.

You have really low chances to get a seat with a rank of 14000 in stream 2. The first round counselling ends on June 22. So if there are some seats you may get but the chances are low only.
You can check the seats available from www.sastra.edu

There are very low chances to get the top branches like CSE, ECE, etc. with a rank of 1815 under stream 1. You may get some rare branches like EIE, mechatronics, etc. but the chances are low as only 2000 AIR ranks are only called for counselling.
You can try for some good courses in the counselling.

No, you cannot. The counselling user stream 1 is held on June 19th, 20th and 21th but the AIR ranks till 2000 are only called. So you may not get it unless you have TNR rank.
If you had got a counselling offer then you may try your luck.

The tuition fees per semester is 55000/- and you need to pay around 10k-20k for hostel and mess fee. So for a year you will be paying nearly 130000-170000.
In all for 4 years you need to pay a maximum of 7.5-8 lakhs.

Remember, any course in SASTRA will fetch you a job in any one of the IT companies at the end of your four years. So, don't restrict yourself to one particular course and be open to any B.Tech course. I have seen people with high marks often choose electronics, experience its wrath and eventually get placed in an IT company. Also, people with lesser marks choosing a lot cooler course to get into an IT company. So, my only suggestion is to be happy with any course you get here. Yes, you will get any desired course that you wanted