Hi Rahul.
What city do you need? Kyiv? For what term?
Please note that good two bedroom appartment in Kyiv now cost 12 000-14 000 UAH per month+utility bills. In winter it is normally more than 2 000 UAH, in summer--less than 1 000 UAH.
For rent appartment it is better to find real estate agent. Their commission is 50% of monthly payment.
Also please note that normally for Kyiv is to pay for the first and the last month.
So if you want to rent two bedroom appartment for a long term, you should prepare at least 30 000 UAH (1 000 EUR in a current rate): 12 000 (first month)+12 000 (last month)+6 000 (commission for real estate agent).
Most houses in Kyiv don't have security. They only have consierge-an old lady sitting on the first floor who controls entrance. The security is an option for business-class level houses. The appartment there cost higher.
If you are Facebook User I could send you links to Kyiv Facebook groups for renting appartment.