In your appointment letter ,the notice period is not mentioned during probation period.
Your employment contract is governed by terms of contract of appointment.
Did the employer issue any corrigendum to apointment letter.
Did the employer any other letter confirmng completion of training period, and initiation of probation period and describing terms etc.Did you sign your acceptance of any adittional conditions.
Hope you submitted your resignation under acknowledgment, and have submitted the company property if any, under receipt.
And employer has not responded to you in writing.
You may submit a reminder to MD,CEO, HR Head, Company secretary,and ask for your acceptance letter, settlement of account,F&F,form16(if any TDs is deducted),work experience certificate,NOC,NDC,releiving letter etc.
Let the employer respond to you in writing.
You may act smart, be persuasive,and resolve amicably with HR.
Or you can lodge greivanc with local labour concilliation officer.