Dear Anjali,

Sorry to inform you that because of your no verification of documents you cannot be able to fill choices in the first counseling round. You have to wait for the second round of counseling and then you can verify your documents along with you'll get the option to fill choices for colleges. Moreover, I would suggest you if possible then visit the help center they can provide you more information, addresses of help centres:

https://cetonline.karnataka.gov.in/dme/assets/Documents/Address%20of%20Helpline%20centres.pdf

For 2018 the second round counseling document verification was conducted on 19 July 2018, for further details visit:

http://kea.kar.nic.in/cet2018/instr_neet_r2_verification.pdf

I hope that'll help you, Best of luck for your further career opportunities.