since property is situated in Mumbai apply for probate of will in Mumbai 

you can apply for probate in Mumbai as property is situated in Mumbai 

Probate is a legal process that certifies the validity and authenticity of a will and grants the executor the authority to execute the will. Probate is mandatory in India when the will is made by a Hindu, Jain, Sikh or Buddhist residing in West Bengal, Chennai or Mumbai, or when the will deals with movable or immovable property situated in these places.

If the property is in Mumbai, but the will is registered in Gujarat, then you have to apply for probate of will in Mumbai, where the property is situated. The competent court to file probate proceedings is the district court of the city/town where the deceased lived at the time of death. However, if the will has been proved and deposited in a court of competent jurisdiction situated beyond the limits of India, or a properly authenticated copy of the will is produced, then letters of administration may be granted by an Indian court of competent jurisdiction to enforce such will.

To apply for probate of will, you need to file a petition along with the original will and other documents to the court. You also need to pay the stamp duty and registration fees depending on the value of the assets. The court will then issue a notice to the next of kin of the deceased and publish a citation to invite any objections from the public. If there are no objections, then the court will grant the probate. If there are objections, then the probate petition will become an original suit and you will have to prove your case through evidence and arguments.

Property situated in Mumbai. Probate will file there only.

- The jurisdiction of filing of the probate petition would be Mumbai where the property is located , and also at the place where the testator has taken last breath. 

- Yes, you can apply for probate in Mumbai, even it is registered in Gujrat. 

if the property is within the jurisdiction of the Bombay High Court then the probate petition has to be filed in Bom HC

Registration of the Will in Gujarat does not determine the Court in which the petition is to be filed

the relevant provision is reproduced below:

INDIAN SUCCESSION ACT, 1925 Section 57 - Application of certain provisions of Part to a class of wills made by Hindus, etc.

Section 57. Application of certain provisions of Part to a class of wills made by Hindus, etc.

The provisions of this Part which are set out in Schedule III shall, subject to the restrictions and modifications specified therein, apply-

(a) to all Wills and codicils made by any Hindu, Buddhist, Sikh or Jaina on or after the first day of September, 1870, within the territories which at the said date were subject to the Lieutenant-Governor of Bengal or within the local limits of the ordinary original civil jurisdiction of the High Courts of Judicature at Madras and Bombay; and

(b) to all such Wills and codicils made outside those territories and limits so far as relates to immoveable property situate within those territories or limits; [and

(c) to all Wills and codicils made by any Hindu, Buddhist, Sikh or Jaina on or after the first day of January, 1927, to which those provisions are not applied by clauses (a) and (b):]

Provided that marriage shall not revoke any such Will or codicil.]

Thus if the Will was signed and executed in Gujarat and makes a bequest of a property which is within the local limits of jurisdiction of the Bom HC then probate for that Will has to be filed in the Bom HC [section 57, clause b, Indian Succession Act, 1925]

As per section 270 of the Indian Succession Act, petition for probate shall filed before the district court  where the testator(deceased)  lastly reside or had a fixed place of abode or where the property mentioned in the Will situated . In case, if he died in Gujarat, petition for probate can be filed before the district court at Gujarat. Asif, invoking the property jurisdiction, petition can be filed before the Bombay High Court. The High Courts of Bombay, Calcutta and Madras have jurisdiction to decide the probate petition.

You have to apply in Mumbai court for probate of WILL and not in Gujarat as its already registered WILL in Gujarat state. 

If you could have registered same WILL in Mumbai than no need of Probate  procedure required.

If there is no other property other than the property located ion Mumbai then it would be proper to obtain probate from the court competent at Mumbai.

Yes, you have to apply for grant of probated at Mumbai only.

In Mumbai 

Jurisdiction shall vest with the Court where the property is situated and not where the Will is executed.