Credit Card against FD( Need suggestion)

Hi guys am 19 year old student and I need an ipad for my studies I tried getting it on my Fathers sbi credit card on emi but limit on credit card is less than the price of ipad I tried increasing limit but sbi is rejecting it…..now the point is my parents are sayin that i should buy on full payment and I am thinking to get a credit card againt fd for the amount something around 75-80k and Ill pay the emi through that as it will also increase my cibil score for future and i will easily be able to pay every month the emi( i mean there will be no due payment) but i am confused on how actually these credit cards works I tried researching on Youtube but am clueless……Can you guys please suggest me something:-

1.How these credit cards works 2. What does this fd actually mean 3. When I will close the credit card what about the money that i deposited for fd 4. What are some credit cards that are best in these scenario