My case is "Case Received". How much time from now on?

My case has been selected in the lottery in regular processing FY2017. Now, how much time should I expect, will they take in regular processing for taking decision further (Approval or Rejection).

Processing can take 2-6 months or longer under regular processing. If RFE is issued, then it can take longer.

But I have heard that they cannot drag it on later than 1st of October. Is this correct?

Oh they can. There are still folks who applied in April 2015 and are still waiting.