After trying a lot of things, I finally had success. H&R Block software came to my rescue. I could _not_ find a way to import txf format files in online version of the software. So, I contacted their support via chat and the support person said the following::
"The Software Program can accommodate up to 6,120 capital gains or loss entries at a maximum total value of $999,999,999.00 and no more than $9,999,999.00 per transaction. However, the client will be required to print and mail if they exceed 250 capital gains transactions on their return."
I purchased H&R Block at Home, Premium Edition (the desktop version) after this discussion and it was able to import transations from txf format file (which I got from my Ameritrade account) and it did not run into the limit of $9,999,999.00 which TurboTax Premier desktop edition did .
I have not submitted my taxes yet but I ran error check and everything worked fine. I dont know if it will require me to mail the tax docs like the support guy said or willl it let me efile. Either way, it is not a big deal for me because atleast it allowed me to finish my taxes which the TurboTax desktop version did not.
Thanks to Johnny P from H&R block support team.
Posting all this in case anyone else needs this info and may be it will help someone else.