Take a call - meaning in the following context

Solution 1:

Oddly, there is a sense where "take a call" means "not decide", vaguely similar to a sense of the idiom "take a rain check". I suspect it somehow relates to umpiring in sports, but I don't know what the specific analogy would be.

It's impossible to be sure which of the several senses of "take a call" was intended in the OP's snippet, but my guess is that it meant "I need to defer the decision until I get more information (presumably from the second opinion)".

Solution 2:

"Take a call" is a phrase specific to Indian English. It means the same thing as "make a call" which is to make a decision or a judgement.