Mothers will

Show the will to a local prudent lawyer for proper analyses and advise as no opinion can be formed on the basis of facts posted by you, which are incomplete and vague.

If the property was your mother's own and absolute property then the Will written by her bequeathing the property to your sister would be valid and your proposed claim through court may not be maintainable. 

There are two door numbers to two floors. She bequeathed only door no 56 to my sister. The will does not say anything about door no 56/1 which is also present. Can I claim door no 56/1?

As far as the Will is concerned, it is clear tht the property bequeathed in Will is available, if there are any other property which have not been included in the Will, then it will not ba a part of the Will bequest.

If that property also belonged to your deceased mother, then it will be subjected to intestate succession.

In that case being one of the legal heirs you will be entitled to a share in that property as a right.

Was she the absolute owner of he property? Or, is it that the property belonged to your late father?

If your mother is also owner of door9

 no 56/1 and she did not bequeath this property to anyone then you can claim your respective share in property door no 56/1.