Inform me of the locationwhere you would like to have lunch.The underlined clause is an example of

• Inform me of the location where you would like to have lunch. The underlined clause is an example of an Aadjective clause.

• Adjective clause:
- যে sub-ordinate clause কোনো noun/pronoun এর পরে বসে ঐ noun/pronoun কে modify করে তাকে Adjective Clause বলে। 
- অর্থাৎ noun এর post modifier হিসাবে adjective clause বসে।

• Adjective Clause দুইটি স্থানে বসতে পারে - 
- Noun এর post modifier - (subject + verb + noun + adjective clause) 
- Subject এর  post modifier - (Subject + adjective clause + verb + object)

• Inform me of the location where you would like to have lunch.
- বাক্যে 'where you would like to have lunch' clauseটি the time (সময়) nounটিকে modify করেছে।
- তাই এটি হচ্ছে Adjective clause.