Hi Vinod, I'm an archivist or that's my day job. Ethically speaking I can't recommend an appraiser, but you may want to find one through an appraisal society. https://www.appraisers.org/ I'm sure you can locate one near you. There may be a fee involved if you do want to go through the process but that can be asked ahead of time. Also, you may want to rehouse the collection of photos in archival sleeves, mylar would be your best bet and we order our supplies through Gaylord. https://www.gaylord.com/ They are a little more pricey than what you would find at an office supply store for photos but well worth peace of mind and preservation of treasured photos
Vince.