Components:

Since most of the components are bought through mouser shipping and custom charges will be included extra. (Assuming 30% extra then material cost given in online store) = 6930 Rs. (and 40% of the cost is just 2 arduinos, Lol chip shortage is real)

PCB Printing:
I used pcbway estimator to calculate the cost (https://www.pcbway.com/HighQualityOrderOnline.aspx)
My board is 58mm x 38 mm, 2 layer => $ 116 ~ Rs 8900

Assembly:
All the components are either through hole or 0805 package, hence it can he hand soldered. Assuming this assembly charges will be only the soldering lead and consumables used. Hence  Rs.250 can be accounted for assembly.

Miscellaneous costs: (transport and other stimulus need) Rs 1000 
Total Cost for 2 prototypes = Rs. 17080