To increase baby weight you can follow the given diet chart.
Fruits: all fruits except citrus fruits
Vegetables: all seasonal vegetables
Cereals & Grains: almost all cereals and grains
Pulses: Yellow Moong Dal, masoor dal, chickpeas (white & black chana), urad dal, green gram, toor dal, bengal gram dal, soybeans
Dairy: all dairy products except cow’s milk
Non Vegetarian: egg yolks, minced chicken, fish
Spices: Turmeric, garlic, ginger, asafoetida, cumin seeds, pepper, coriander seeds, fennel seeds, caroms, fenugreek, mustard seeds, cinnamon, nutmeg, cardamom (all can be added in little amount say a pinch)