Upvote:-2
I believe that the passports are actually, physically, sent to the United Kingdom where the visa application is processed and decided.
British Embassy Berlin - GOV.UK - Visas
UK Visas & Immigration (UKVI) is responsible for all Visa matters. The British Embassy does not deal with visa services and cannot advise you on visa matters.
(This probably does not apply for all countries)
Only special Visa Application Centres exist where a special, faster, service is available.
Assuming that this is correct and your withdrawal request was Friday morning (in India), the time needed to transport the passport from the UK to India per post (after the withdrawal request was processed in the UK (which may, or not, take place Friday morning UK time), packaged and sent off) would have to be calculated (assume that on the weekend nothing will happen).
After arrival back in India, further processing at the Visa Application Centre should be added to that time.
Six days (including the weekend), seems to me, to be unrealistic.