Once the Ishraq time starts, is it permissible to pray Chasht salah after Ishraq salah?

بسم الله الرحمن الرحيم

(Fatwa: 965/774/B=8/1439)

Yes, it is lawful. The timing of both the salah is same.

Allah knows Best!

Darul Ifta,
Darul Uloom Deoband