Credit rating report - http://www.icra.in/Files/Reports/Rationale/APL%20Apollo-R-07062016.pdf
No shares pledged by promoter as per annual report
I see minimal risk of a short term liquidity crunch. In fact the company has been able to stay steady over the past 2 years when commodity prices were getting hammered and the banking sector was under severe pressure to clean up NPA, I think the worst period is already past. If anything the credit rating will only improve from here, relative debt levels (D/E) will stay steady at worst and get better if you go by the base case scenario.
Disclosure: I am biased in favor of the company, please read all my posts with this perspective.