A new D2R roadmap has been released, along with PTR timings and expectations for the new patch. PTR 2.4 will pave the way for D2R's first ranked ladder and will test a number of things including season rolls and item scroll over. The development team hasn't revealed the exact date of ladder reset, but MMOWTS speculates it could come in April.
Diablo 2 Resurrected ladder reset may be in early or mid-April, according to the updated information on the roadmap. A more likely time is April 4-10, or April 11-17.
Blizzard has not officially confirmed a new ladder reset date, as the PTR test has not yet been completed, and there may be some unforeseen issues, consequences, or final tweaks that need to be done before the ranked mode is ready.
The development team says they expect to release the ladder within a week or two after the 2.4 update hits. One to two weeks is enough for them to make sure that the upcoming issues can be resolved. They need to ensure that the integrity and competitive nature of the ladder do not run into any snags.
Once the Diablo 2 Resurrected ladder is released, you can always come to MMOWTS to buy Diablo 2 Resurrected Items to help you get a better gaming experience. Since you'll be starting over in the ladder, purchasing D2R Items will help you gain an advantage quickly and become an in-game leader.