I am searching the place in my apps using the google autocomplete place api and now I want to get latitude and longitude of the place that i have searched. How to get latitude a
Each place returned in the place-autocomplete response has an Id and a reference string as explained here.
Use either (preferably Id since reference is deprecated) to query Places API for the full information about that place (including lat/lng): https://developers.google.com/places/documentation/details#PlaceDetailsRequests
Regarding shyam's comment - Geocoding will work only if you got a full address in the autocomplete response which is not always the case. Also Geocoding gives a list of possible results since the place description you get in the autocomplete response is not unique. Depending on your needs, geocoding might be enough.