After partition, East Court of Punjab was established at

Delhi
Chandigarh
Shimla
Lahore

The correct answer is A. Delhi.

The East Court of Punjab was established in Delhi in 1947 after the partition of India. The court was responsible for hearing cases from the eastern part of the Punjab province, which had been divided between India and Pakistan. The court was abolished in 1956 when the Punjab province was reorganized.

The other options are incorrect. Option B, Chandigarh, is the capital of the Indian state of Punjab. Option C, Shimla, is a hill station in the Indian state of Himachal Pradesh. Option D, Lahore, is a city in Pakistan.