How to compute reasonable expected rent while computing gross annual value of a property which is let-out throughout the year. ?
Reasonable expected rent will be higher of the following:

Municipal value of the property (Note 1); or
Fair rent of the property (Note 2).

If a property is covered under Rent Control Act, then the reasonable expected rent cannot exceed standard rent (Note 3).

Note 1: Meaning of Municipal Value

For collection of municipal taxes, local authorities make periodic survey of all buildings in their jurisdiction. Such value determined by the municipal authorities in respect of a property, is called as municipal value of the property.

Note 2: Meaning of Fair Rent

It is the reasonable expected rent which the property can fetch. It can be determined on the basis of rent fetched by a similar property in the same or similar locality.

Note 3: Meaning of Standard Rent

It is the maximum rent which a person can legally recover from his tenant under the Rent Control Act. Standard rent is applicable only in case of properties covered under Rent Control Act.