None of the properties mentioned by you (either the house property purchased by your father from his income, or the house built by your mother by using the money received by her from her parent's property).
NONE OF YOU, whether you or your sister have any right to ask or demand any share in the said properties, especially when your parents are alive.
It is only when either of your parents pass away (then the property standing in his or her name), that too if they do not leave any WILL, make any gift or so, then the said property will go by way of inheritance amongst the class-I heirs (i.e. your mother, you and your sister) or alternatively (your father, you and your sister).
You are not very clear, whether any GIFT DEED was executed by your father in favour of your sister. If so, whether there is any condition stated therein. Since you say that your sister is asking them to vacate the property since the same is in her name, one has to presume that probably your father had GIFTED the said property to your sister.
In case there are any conditions in the GIFT DEED, and if those conditions are being breached by your sister, then your father can get the GIFT DEED cancelled by approaching the Court.
All these things will get clear only when a lawyer could go through the relevant documents. Therefore, please consult a local lawyer well versed in property matters, show the documents and then take appropriate steps.