i belong to a.p state board our 12th marksheet contains aggregate out of 1000 but the board cut off are given out of 500 how are marks reduced to 500 for board which gave toral marks out of 1000 ? pls help some sir just said me it is scaling down by unitary method can you explain me how it is done i have got 799/1000 in 12^th in 2016 will i be eligible for admission to iit/nit in 2017

@ sourabh 
yes , u are elligible for the jee advanced 2017 as your percentage is above 75 , thats the only criteria required for the attemption for jee advanced 2017 . 
and about that 500 and 1000 , that happens beacuse of the optional subject , actually for normalisation in jee exam , they will take some subject like maths , phy and 1 opt and 1 language , not all subject . 
for that reason i think its reduced to 500 as for every board its nearly 500 . 
but every board normalisation criteria are diffrent . 
ALL THE BEST ..