At 36 weeks baby ja weight 2.6 kg honi chahiye aur aapka baby usse kam weigh kar raha hain.
Please have a healthy diet lots of fruits, veggies, milk, curd, cheese, legumes, pulses, sprouts, soybean, peas and beans, chicken, fish, eggs, carrot, sweet potato, nuts, whole grain cereal etc.
Have plenty of water.
Keep yourself active.
Discuss with the Doctor if he wants to prescribe any supplements for the weight gain of the baby.
Be positive and good luck!