Here's an ideal itinerary for 3 days in Bengaluru:

Day 1:

• Start your day with a visit to the Lalbagh Botanical Garden, one of the most popular tourist attractions in Bengaluru. You can take a stroll through the beautiful gardens and enjoy the serene atmosphere.
• Next, head to the Bangalore Palace, which is a stunning example of Tudor-style architecture. You can explore the palace grounds and learn about its history.
• For lunch, head to MTR (Mavalli Tiffin Room), a famous restaurant that serves authentic South Indian cuisine.
• In the afternoon, visit the Tipu Sultan's Summer Palace, which is a beautiful example of Indo-Islamic architecture. You can learn about the life and times of Tipu Sultan, who was a prominent ruler in the region.
• End your day by visiting the UB City Mall, which is a high-end shopping destination in Bengaluru. You can shop for luxury brands or enjoy a meal at one of the many restaurants.

Day 2:

• Start your day by visiting the ISKCON Temple, which is a beautiful temple dedicated to Lord Krishna. You can attend the morning prayers and soak in the spiritual atmosphere.
• Next, head to the Cubbon Park, which is a large public park in the heart of the city. You can take a walk through the park and enjoy the greenery.
• For lunch, head to Vidyarthi Bhavan, a famous restaurant that serves delicious dosas and other South Indian delicacies.
• In the afternoon, visit the Bangalore Fort, which is a historic fort built by Kempegowda, the founder of Bengaluru. You can learn about the history of the fort and explore its ruins.
• End your day by visiting the Brigade Road, which is a popular shopping and entertainment destination in Bengaluru. You can shop for souvenirs or enjoy a meal at one of the many restaurants.

Day 3:

• Start your day by visiting the Nandi Hills, which is a scenic hill station located about an hour's drive from Bengaluru. You can enjoy the beautiful views and take a walk through the hills.
• Next, head to the Bull Temple, which is a famous temple dedicated to Lord Shiva's mount, Nandi. You can learn about the history of the temple and admire its architecture.
• For lunch, head to Koshy's, a famous restaurant that serves delicious Continental and Indian cuisine.
• In the afternoon, visit the National Gallery of Modern Art, which is a museum that showcases modern and contemporary art from India and abroad. You can explore the galleries and appreciate the artwork.
• End your day by visiting the Phoenix Marketcity Mall, which is a popular shopping destination in Bengaluru. You can shop for clothes, accessories, and electronics or enjoy a movie at the multiplex.