Hey aaradhana!

To become an IAS , all you need is hardwork and smart study. If  you have any financial issues , then this can not stop you from becoming an IAS. Many poor students qualify IAS eveery year and get good ranks as well. 

So , you can do self study for IAS .You can also clear IAS without joining a coaching.

You can find all the study material for your preparation for free on careers360 website.

You can download the free books , sample papers , previous year question papers for IAS on this website only.

You just need to follow the given link:

https://learn.careers360.com/jobs/ias-question-papers/

If affordable , then you can buy some common preparation books for indian economy , general awareness etc.