Hello Surbhi, hope you have done well in NEET 2019. You cannot upload your NEET rank right now because it's still not out. Once the result is out, IISc Bangalore will open their portal within 2-3days of NEET result to upload your NEET rank. You can easily upload your rank by simply login to their portal with your email id and password you have given during registration. 

Hope this answer gives you the information you required.