I am looking for places from where I can buy low risk securities (like money market funds). Basically I want to invest my emergency fund in these kind of investments in order to keep up with inflation.
Money markets & CD make so little now, it's hardly worth the effort of moving the money around.
There is another option that meets your requirement that it keep up with inflation. That would be
I Savings Bonds. These federal government bonds that are like those old school savings bonds that grandparents used to buy their grandkids -- with the twist that the interest earned is in two parts - a fixed percentage interest, and a variable one that matches the official inflation rate.
That combined rate is set twice a year. Currently, it's 3.06% combined. That's all inflation. The fixed interest portion of I-bonds issued now is 0%.
These are designed for individuals, and can be bought direct from the government at http://www.treasurydirect.gov/indiv/indiv.htm .
Note you have to hold them for at least a year before you can redeem them, so you'd want to ease into them over time.