Call KCC and let them know you will be filing i-485. They will let you know if you need to fill ds 260. I think you have to but make sure with KCC. Watch visa bulletin and get heads up when will be your case no current. Good luck.

Thanks Ustadamirkhan. Looks like the call to KCC is temporarily suspended these days. I always end up with virtual support only when I call to USCIS too.
Also, I had recently filed i-140 for immigration with employment based visa (EB2). USCIS hasn't made any decision regarding my EB2 application yet. I think EDV process is faster than EB2 process. So, I am thinking to stick with EDV at this moment. Am I doing right?

Visit USCIS website for more info.
https://www.uscis.gov/green-card/green-card-eligibility/green-card-through-the-diversity-immigrant-visa-program

DS 260 is basically a formality. KCC will only forward your case to USCIS and USCIS will be doing most of your work. Fill in DS 260 and indicate that you will be doing adjustment of status. The paperwork for AOS is intense with USCIS so start preparing everything ASAP so you have the packet ready to go when your priority date comes. Keep checking the visa bulletin. DV winners also get a couple weeks headstart since you can apply almost a month before your priority date is current.

For now....fill in DS 260. Start preparing packet for USCIS. If it does not get processed by the deadline, you lose your visa, which is very rare because USCIS puts DV cases in the front of the line but its never bad to be more proactive. Use every day in your favor to provide USCIS as much time as you can possibly provide. Hoping your case number is not high, the higher it is the later in the fiscal year you can send in your packet. Remember you can only send the packet once your case is current but you can have the packet prepped in advance.

Thank you. I appreciate you all for the information.

Oe_jharpat ji, I didn't see option of paying DS 260 application fee while submitting the form online. It looks like the online payment is disabled for this application (I tried multiple times). So, I sent a cheque to Department of State (DOS) around 7 days ago and waiting for the payment receipt. Does DOS send payment receipt? It looks like I will need to include DS 260 payment receipt while I send documents to USCIS for adjustment of status. Do you have any suggestion for DS 260 application fee payment or sending documents to USCIS without waiting payment receipt from DS 260?