Please check the sender address, i.e. the "From" email address, to ensure that the email you received from Kotak Securities is authentic. The email address's second half should be one of the following:
kotaksecurities.co.in
kotaksecurities.biz
info.kotaksecurities.co.in
services.kotaksecurities.co.in
research.kotaksecurities.co.in
kotakneo.com
nmail.kotaksecurities.com