Employer not giving relieving certificate

first of all you cannot be forced to serve without will.  it is violation of dundamental right (you have not disclosed if you have signed any congtract)

experience certificate cannot be compelled.

You simply should submit resignation and the experience certificate is not your right for just serving a short duration. You might be still in probation. IF there is any signed contract between you and your employer then you have to adhere the terms therein.

You have to follow terms & conditions as per your appointment letter from the employer. An employee must clearly state that they intend to end their employment otherwise it may very well consitute reasonable grounds for abandonment.