Here are some definitive links to get you started with your Smart India hackathon Prep:
1.) Problem statements can be accessed: https://www.sih.gov.in/sih2020PS
Please note that as of 08/12/2019 not all problem statements are announced, so if you don’t find something you want to do, it might be worthwhile to wait it out.
2.) You should probably also read the FAQs: https://www.sih.gov.in/pdf/Student%20FAQs.pdf
3.) Follow i4c (Inter Institutional Inclusive Innovations Center) on facebook: https://www.facebook.com/i4C.India/
Note: This is pretty much the only way to get any useful updates about SIH. From personal experience, the app is very infrequently updated and this page is your best bet to get doubts cleared.
4.) Download the SIH App: https://play.google.com/store/apps/details?id=com.psl.sihapps&hl=en_IN
This is mandatory for the competition. So might as well do it.
5.) This Video is a pretty comprehensive Q&A for SIH in general: Inter Institutional Inclusive Innovations Center - i4C - SIH 2019 Introduction and Q&A | Facebook
6.) For the hardware edition, this is what they’re looking for: Inter Institutional Inclusive Innovations Center - i4C - Prepping for SIH2019 Hardware Grand Finale | Facebook
Note: You need to have a team of 6 members with at least 1 girl in it, so keep that in mind. It’s always useful to have a couple of industry mentors who’d be willing to go with you to the venue (and help you code!). I didn’t, and even though I won my job would have definitely be easier if I had a few adults to deal with all the bureaucratic stuff (there’s a lot of it at SIH).
All the best with your preparations! If you have any questions regarding any of the above in mind, please comment here. I will be making another post for preparation strategies soon.