26as

I am a pensioner from Osmania University Hyderabad.  I normally file my returns on line by first or second week of April, every year. However from last year, University started deducting TDS and I had to wait till form 26AS is available.  I also find that the TDS deducted is credited very late by University - may be 3 or 4 months.  Is there any STATUTORY TIME LIMIT SPECIFIED BY GOVERNMENT by which time the emploer has to  pay the TDS to the IncomeTax , thereby AS26 is updated? Since I do not want to loose the credit in 26AS, I do not want to take the risk of filing returs early. University Authorities do not answer satisfactorly why TDS is not reflected in 26AS.  As retired pensioners, we can not be running from pillar to post with such questions.  What is the remedy, and how long should I wait before I file reurns?