Office PC for 15K - Advice needed

Hi guys, a friend is planning to build a PC for office use. I did look at the buying guide. But since many components mentioned in the guide are not needed, thought it is better to have it customized better for the budget. I have given the details as per the template. Kindly let me know if some more details are needed.

1. What is the purpose of the computer? What all applications and games are you going to run? (Stupid answers like 'gaming' or 'office work' will not work. Be exact. Which games? Which applications? Avoid the word 'et cetera.')
Ans: Office use - Microsoft Office, Tally and Web Browsing.

2. What is your overall budget? If you can extend a bit for a more balanced configuration, then mention this too.
Ans: 15K. Can extend to 16K max.

3. Planning to overclock?
Ans: Nope

4. Which Operating System are you planning to use?
Ans: Windows 7/10

5. How much hard drive space is needed?
Ans: 500GB

6. Do you want to buy a monitor? If yes, please mention which screen size and resolution do you want. If you already have a monitor and want to reuse it, again mention the size and resolution of monitor you have.
Ans: Monitor is already there. Size - 21.5", 1920x1080

7. Which components you DON'T want to buy or which components you already have and plan on reusing?
Ans: Want to buy CPU, Motherboard, HDD, RAM, Cabinet and PSU. Do not want/need a discrete graphics card.
Monitor, Optical drive, Keyboard, Mouse and Speakers from the current setup will be used.

8. When are you planning to buy the system?
Ans: Within a week.

9. Have you ever built a desktop before or will this be done by an assembler?
Ans: Yes, buyer has experience. Will be built by himself.

10. Where do you live? Are you buying locally? Are you open to buying stuff from online shops if you don't get locally?
Ans: Bengaluru. Online shops are preferred.

11. Anything else which you would like to say?
Ans: Nope

Thanks in advance.