What happens to the transactions included in the forks? Let:

a) the vector triplet &lt;x,y,z> refer &lt;height, index, parent_index>

b) blocks, block100, block110 (of height 1) are mined together and they both refer previous block block00[null] (of height 0).

Block, block110 (of height 1) gets a child block and its branch grows but 

block block100 doesn't get any child block till then and became leaf/fork.

Please advise what happens to the ith transaction t100i of block, block100 that is not included in the branching block, block110.
On nodes that had accepted block100: when they disconnect it to reorg they will remember the transactions in it and attempt to reinsert into the mempool any that fell out once they finish the reorg. If they're still valid, they'll be added and queued for mining in a future block.

On nodes that initially accepted block110: the transactions that were still valid after accepting the block will remain in the mempool queued for mining in a future block.

Transactions which were invalidated by other transactions included in block110 are forgotten by nodes.