Hi Shankar,

GFTIs admission criteria do not depend upon your financial condition. For admission in any GFTI is only through JoSAA counseling and to participate in JoSAA counseling you have to give JEE MAIN examination and clear the exam along with rank under 30-40k. After that, you have to fill up JoSAA counseling procedure and GFTIs of your preferences. After that counseling, the result will be declared and you will be allotted a college based on your rank.

For the fees part, most of the GFTIs have their fees in the order of 1lakh per annum to 2 lakh per annum, however, if you can not afford this fee there are many scholarship programs in GFTIs for economically weaker students and also there are some seats reserved for economically weaker sections of the society under the reservation of TFW(Tuition fee waiver). 

You do not have to worry for the fee that much, just prepare with full hard work for the exam. 

All the best.

Here are some helpful link:-

https://engineering.careers360.com/exams/jee-main

https://engineering.careers360.com/articles/nits-cutoff-for-top-btech-branches

Comment your doubts, if any.

Thank you.