Formatting number

there is no intersection of digits between the first and second number formed. Thus the two numbers can be any 3-digit multiple of 11. There are 81 3-digit numbers which are multiples of 11 (take the floor of 999/11 and subtract the floor of 99/11). Thus the total combinations is 81^2=6561

We know, if a 3 digit number's sum of 1st and 3rd digit then subtract by 2nd digit and result come 0 or 11,we can say, that number should be divisible by 11.

Now, the way to make the number of 3 digit keeping 0 in middle,

902,209,803,308,704,407,605,506 (8 times)

the way to make the number of 3 digit keeping 1 in middle,

110,319,913,418,814,517,715,616 (8 times)

the way to make the number of 3 digit keeping 2 in middle,

121,220,429,924,528,825,627,726 (8 times)

the way to make the number of 3 digit keeping 3 in middle,

132,231,330,539,935,836,638,737 (8 times)

the way to make the number of 3 digit keeping 4 in middle,

143,341,242,649,946,748,847,440 (8 times)

the way to make the number of 3 digit keeping 5 in middle,

154,451,253,352,858,957,759,550 (8 times)

the way to make the number of 3 digit keeping 6 in middle,

165,561,264,462,363,869,968,660 (8 times)

the way to make the number of 3 digit keeping 7 in middle,

176,671,275,572,374,473,979,770 (8 times)

the way to make the number of 3 digit keeping 8 in middle,

187,781,286,682,385,583,484,880 (8 times)

the way to make the number of 3 digit keeping 9 in middle,

198,891,297,792,396,693,495,594,990 (9 times)

That is to say, thus 3 digit number can format = 9x8 +9 =81

Now 6 digit number can make =81 x 81 = 6561 (Ans.)