Hii,
I am new here on Freelancer platform, So you will not see any reviews and ratings on my account but I am an experienced Android developer having over 3 years of experience in Android development. Developing Android apps is my day to day life.
I have read your project requirements carefully. And from that what I can say is
I can extracts contacts from your text file and save each and every number on your phone.
But from Telegram App, you have to invite all of the contacts, because AFAIK Telegram is not providing any API that lets you invite a contact from API.
So, basically, I can extract each and every number from your text file and save them into your phone.
If this is enough for you then please let me know
And If you have any doubts or queries then feel free to ask me.
Give me one chance and I can guarantee you that you will not regret the decision of working with me.
Thank you