Rice and veggies are a good option. Among veggies stay away from onions, grapes and grape products (resins), tomatoes and garlic. Papaya, pumpkin, carrots, beans, mashed peas, spinach are good veggies. While apples are good too, make SURE to remove the seeds. Apple seeds contain small quantities of cyanide that is very dangerous for dogs.
Take care of protein and calcium. Calcium will come with milk and soy chunks and egg whites will give necessary protein. Ragi is also a good substitute for rice, since it contains protein as well.
Depends on the age of your puppy. If your puppy is in a rapidly growing age, then stick to puppy food like RC. If your puppy is nearly adult weight, then consider home food.
Home food is good :) We put love and care into the food we cook which no packaged food can give. So, depending on age of the dog, you can decide if you want to introduce home food. There are several different theories on this and none of the studies are conclusive. So you have to do what your gut tells you is best for your doggie.Just make sure that during growing days, your dogs nutritional needs are taken care of.