She told that she ________ Dhaka next month. Here the right form verb will be -

• Grammer rule: 
• Main clause এর verb টি past tense হলে এবং পরের অংশে next day, next week, next month, next year ইত্যাদি উল্লেখ থাকলে subject এর পরে might/would/could বসে এবং এরপর verb এর base form বসে।

• শূন্যস্থানে সঠিক উত্তর হবে - would visit.
Complete Sentence: She told that she would visit Dhaka next month.

Example Sentence:
1. Sarah told Marzia that she would visit her parents the next week.
2. Jason told Benson that he would complete the project the next month.
3. Pori told Mahiya that she would join the gym the next day.
4. Emma told Lima that she would buy a new car the next year.