1: Might remains unchanged in reported speech.

Bilal said, "I might leave for Karachi today." Direct speech
Bilal said that he might leave for Karachi that day. Indirect speech

BUT when might is used for request, it changes.

Humaira said, "you might bring some flowers for me please." Direct speech
Humaira asked him to bring her some flowers./ Humaira requested him to bring some flowers for her. Indirect speech

2: Ought to and should remain unchanged when used in their original role i-e for obligation and assumption.

Ali said, "He should not tease his sister". Direct speech
Ali said that he should not tease hi sister. Indirect speech.

My father said, "You ought to respect the elders". Direct speech
My father said that i ought to respect the elders. Indirect speech

BUT when it is used for advice it changes, advise + object[/COLOR]

"You should work hard to succeed", said his father. Direct speech
His father advised him to work hard to succeed. Indirect speech

3: should be, would be grateful for making requests is reported by
ask + object +infinitive.

"I would be grateful to you if you would lend me five rupee", said Hamza. Direct speech
He asked me to lend him five rupee. Indirect speech
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Exercise:

He said, "We should help the poor".
Bilal said, "we might go to Switzerland for our honeymoon".
"You ought to take care of all students", said my teacher.
She said, "You might fetch me a glass of water."
"I would be thankful to you if you'd tell me hi name", said Ali.

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Ever has it been that love knows not its own depth until the hour of separation.
But when love is one sided, holding off is no more an option.