Let us consider the sentences in order.
Sentence 1- Khap panchayats are extra-constitutional bodies in Haryana that decry (A) /decree (B) institutionalised atrocities.
“Decry” means to condemn or speak disparagingly of
“Decree” means to command or ordain
Either of the words might be the right choice to fit in this sentence. We need to read the rest of the sentences to understand the context.
Sentence 2- The Khap leaders are universally criticised for imposing regressive diktats that fetter (A)/curb (B) women.
The passage is talking of Khap panchayats “imposing regressive diktats”. So the correct word for sentence 1 is decree, not decry.
Now for the correct word to choose in sentence 2:
“Fetter” means to confine or restrain. “Curb” also means something similar, to restrain or check. But considering the object in question, women, “fetter women” makes better sense than “curb women”.
Sentence 3 - Patriarchal and misogynist, Khaps have played a key role in reducing Haryana’s sex ratio to an immeasurable (A)/abysmal (B) low.
“Immeasurable” means incapable of being measured.
“Abysmal” means very deep or great.
The right choice here is abysmal. Haryana’s sex ratio has been reduced to a great low.
Sentence 4- The recent apex court directive against Khap panchayats holds the district administration including the police accountable for the prevention of the barbaric acts carried out at the behest (A)/recommendation (B) of the Khaps.
“Behest” means command or directive. It makes better sense here than “recommendation”, which is a weak substitute.