Which house to take for father Is yet another controversial topic within the jyotish community. However such controversies are often dispelled simply by understanding the logic behind the issue.
As we know 9th house is traditionally accepted in the South of India as being the house of father whilst learned pundits in the North of India see father from 10th house. The amazing thing is that both claim their predictions to be reliable even though the predictions are based on different houses - how can this be? Logic tells us that it's not possible for both houses to have consistently reliable results.
This topic was raised on JyotishVidya discussion group some time back and it was pointed out that as 10th house (father) is 7th from 4th (mother) it's obvious that 10th shows the mother's husband as father of the native. Logic dictates that this is correct and learned Pundits from North India agree. I put the argument forward that, as 9th house is 6th from 4th, this would rightly represent the mother's uncle (6th being the house of maternal uncle). I argued that this therefore was just not logical and considered it to be the end of the argument.
However I later learnt that it's long been the tradition in Southern India for women to marry their maternal uncle - mother's brother. I've been told it's still the practice in some villages but I can't vouch for this. So we can see clearly where the tradition of 9th house for father has sprung from, and we can now understand the reason why astrologers in Southern India swear that 9th house gives consistently reliable results - of course it does!
As the 9th is the house of Guru or Spiritual father and because, in India particularly, one's own father traditionally passed down his knowledge (Vedic sutras etc.) to his offspring, father, in this light, can also be seen from 9th house.
Westerners today have taken to the Vedic sciences (including jyotish) like ducks to water; this ultimately has to be a great blessing for Western society. However the unprecedented explosion of jyotish teachers and organizations that have sprung up in most Western countries to teach and regulate this divine science is, to me, more than a little disconcerting. Knowledge without discernment can easily become distorted and, with the easy flow of information on the internet, such distorted knowledge can spread like wildfire.
Controversies such as ayanamsha, aspects of Moon's nodes, house of father and so forth are important issues that require some insight to understand correctly. Unfortunately many, with big reputations, seem to lack the proper insight. It's a blight on jyotish that so many of these new vogue gurus teach that 9th house represents father. Well, I'm sorry to say, that unless the native is from Southern India (or some other Country that follows the same tradition), this is highly inappropriate.