What should i feed my double coated gsd??

i am also from jharkhand,ranchi so i know your situation.to help him gain weight you can give him boiled egg or chicken with rice and you should supplement him with salmon oil and multivitamin paste of a good brand ,you should also deworm him because that may be the cause of his low weight .after doing the above you will see an assured improvement

I am deworming him using ALBOMAR, and also giving him PROVIBOOST and NUTRICAL CA, I have doubled the quantity of his dry foods drools focus puppy(Supreme quality)

The food you are feeding is a good quality food. No need to add anything and unbalance the nutrition ratio. Also, stop with the multivitamins! Your dog food should contain everything in it, adding anything extra only ruin everything, and especially with a large breed pup you don't want to overdose calcium phosporus ratio.
One of the proven way to put weight on a skinny canine is "satin balls" i'm providing you the recipe however make sure to discontinue using it once the pup fills up a bit.

10 pounds raw ground beef, 70%-85% lean 18 ounces Total Multi-grain cereal (or other vitamin-fortified, unsweetened cereal 2 pounds oatmeal, uncooked regular or quick oats (not instant oats) 20 ounces wheat germ 1 � cup canola oil 1 � cup unsulfured molasses 10 hard-boiled eggsand shells, crushed and minced 10 envelopes unflavored gelatin � teaspoon salt 1 teaspoon minced garlic

Combine all ingredients and mix well. Divideinto freezer bags in daily ration portions (some divide into 10 equal portions, others 14, and I divide itinto one-pound packs). Flatten out the filled bags to expel air and completelyfillthebags, and to reduce freezing/thawing times. Seal and place the bags in the freezer in a single layer. Once frozen, the bags can be stacked. For travel, the frozen bags can be placed in a cooler and used to chill other items until needed. Break thawed meat mixture into chunks or roll into meatballs. Feed raw as a meal or supplement.

Yield: approx. 17 pounds @ 1275 calories/pound.

About the Ingredients

Beef: If the goal is to improve the coat, then use leaner ground beef. If the goal is to put weight on, quickly, then use ground beef with higher fat content.

Cereal: The original recipe calls for Total cereal, but another fortified, unsweetened cereal could be used. Some competing recipes discourage the use of Total cereal �due to its high sugar content�, but since it is unsweetened, the sugar content is low. Total was chosen for the original recipe because of its vitamin content.

Molasses: Some recipes criticize the use of sugar (molasses) in the recipe,howeverthemolassescontr ibutes minerals and calories. If the Satin Balls were being fed on a regular basis, long-term, then one might want to omit the molasses.

Eggs: The original recipe for Satin Balls calls for 10 raw eggs. Apart from concerns about salmonella, raw egg white contains avitin which blocks the use of the B vitamin, biotin. While there is a lot of biotin in the egg yolk, to offset the avitin in the egg white, dogs do not digest raw eggsaswell as they do cooked. Cooking neutralizes the avitin, allowing full use of the biotin. Cooked eggs are more nutritious and easier to digest, with more usable calories per egg, soourrecipe callsfor hard-boiled eggs. The shells are included for their calcium.

Gelatin: Some recipes call for unflavored joint health supplement gelatin.

Other Recipes

I can't see the picture of your puppy btw, maybe because i'm on mobile? Not sure.