Urbane behaviour is characterized by:

• Urbane (adjective)

English Meaning: notably polite or polished in manner.
Bangla Meaning: শিষ্ট; সুসংস্কৃত; মার্জিত; শিষ্টাচারী; শিষ্টাচারপূর্ণ; সুসভ্য।

Hence, Urbane behaviour is characterized by: Smooth and polished social skills.

Example Sentence:
1. The diplomat was known for his urbane manner, effortlessly charming everyone he met.
2. She appreciated his urbane conversation, filled with wit and cultural references.

Source:
1. Oxford Learner's Dictionary.
2. Accessible Dictionary by Bangla Academy.